CpG Oligonucleotide Analogs Containing Hydrophobic T Analogs with Enhanced Immunostimulatory Activity

ABSTRACT

The invention relates to oligonucleotides including at least one lipophilic substituted nucleotide analog and a pyrimidine-purine dinucleotide. The invention also relates to pharmaceutical compositions and methods of use thereof.

FIELD OF THE INVENTION

The present invention relates generally to the field of immunology. More specifically the invention relates to therapeutic oligonucleotides with enhanced immunostimulatory capacity.

BACKGROUND OF THE INVENTION

Bacterial DNA has immune stimulatory affects to activate B cells and natural killer cells, but vertebrate DNA does not (Tokunaga, T., et al., 1988. Jpn. J. Cancer Res. 79:682-686; Tokunaga, T., et al., 1984, JNCI 72:955-962; Messina, J. P., et al., 1991, J. Immunol. 147:1759-1764; and reviewed in Krieg, 1998, In: Applied Oligonucleotide Technology, C. A. Stein and A. M. Krieg, (Eds.), John Wiley and Sons, Inc., New York, N.Y., pp. 431-448). It is now understood that these immune stimulatory effects of bacterial DNA are a result of the presence of unmethylated CpG dinucleotides in particular base contexts (CpG motifs), which are common in bacterial DNA, but methylated and underrepresented in vertebrate DNA (Krieg et al, 1995 Nature 374:546-549; Krieg, 1999 Biochim. Biophys. Acta 93321:1-10). The immune stimulatory effects of bacterial DNA can be mimicked with synthetic oligodeoxynucleotides (ODN) containing these CpG motifs. Such CpG ODN have highly stimulatory effects on human and murine leukocytes, inducing B cell proliferation; cytokine and immunoglobulin accretion; natural killer (NK) cell lytic activity and IFN-γ secretion; and activation of dendritic cells (DCs) and other antigen presenting cells to express costimulatory molecules and secrete cytokines, especially the Th1-like cytokines that are important in promoting the development of Th1-like T cell responses. These immune stimulatory effects of native phosphodiester backbone CpG ODN are highly CpG specific in that the effects are dramatically reduced if the CpG motif is methylated, changed to a GpC, or otherwise eliminated or altered (Krieg et al, 1995 Nature 374:546-549; Hartmann et al, 1999 Proc. Natl. Acad. Sci USA 96:9305-10).

In early studies, it was thought that the immune stimulatory CpG motif followed the formula purine-purine-CpG-pyrimidine-pyrimidine (Krieg et al, 1995 Nature 374:546-549; Pisetsky, 1996 J. Immunol. 156:421-423; Hacker et al., 1998 EMBO J. 17:6230-6240; Lipford et al, 1998 Trends in Microbiol. 6:496-500). However, it is now clear that mouse lymphocytes respond quite well to phosphodiester CpG motifs that do not follow this “formula” (Yi et al., 1998 J. Immunol. 160:5898-5906) and the same is true of human B cells and dendritic cells (Hartmann et al, 1999 Proc. Natl. Acad. Sci USA 96:9305-10; Liang, 1996 J. Clin. Invest. 98:1119-1129).

Several different classes of CpG nucleic acids has recently been described. One class is potent for activating B cells but is relatively weak in inducing IFN-α and NK cell activation; this class has been tamed the B class. The B class CpG nucleic acids typically are fully stabilized and include an unmethylated CpG dinucleotide within certain preferred base contexts. See, e.g., U.S. Pat. Nos. 6,194,388; 6,207,646; 6,214,806; 6,218,371; 6,239,116; and 6,339,068. Another class of CpG nucleic acids activates B cells and NK cells and induces IFN-α; this class has been termed the C-class. The C-class CpG nucleic acids, as first characterized, typically are fully stabilized, include a B class-type sequence and a GC-rich palindrome or near-palindrome. This class has been described in co-pending U.S. provisional patent application 60/313,273, filed Aug. 17, 2001 and U.S. Ser. No. 10/224,523 filed on Aug. 19, 2002 and related PCT Patent Application PCT/US02/126,468 published under International Publication Number WO 03/015711.

SUMMARY OF THE INVENTION

The invention relates to an oligonucleotide which comprises one or more modifications that elicits enhanced immunostimulatory capacity. In particular, the invention is based on the finding that specific sub-classes of oligonucleotides having at least one lipophilic substituted nucleotide analog are highly effective in mediating immune response. These oligonucleotides are useful therapeutically and prophylactically for inducing an immune response and for treating diseases and disorders such as cancer and viral infections.

In ore aspect, the invention is a composition comprising the sequence: R₁YZR₂, wherein R₁ and R₂ represent a lipophilic substituted nucleotide analog (L), a nucleotide, and a linkage, wherein at least one of R₁ and R₂ is a lipophilic substituted nucleotide analog (L), wherein Y is a pyrimidine nucleotide and wherein Z is a purine, a pyrimidine, or an abasic residue.

In some embodiments, L comprises a 5- or 6-membered ring nucleobase analog.

In other embodiments of the aspect of the invention, L is a group of formula I.

having the following elements: A, B, X, D, E, and F are C (carbon) or N (nitrogen) optionally bearing hydrogen or a substituent; n is 0 or 1; the dotted lines indicate optional double bonds; wherein at least one substituent is not chosen from the group consisting of oxo, thio, hydroxy, mercapto, imino, amino, methyl and hydrogen, and that the total of A, B, X, D, E and F atoms is not more than 3 nitrogens (N). In some cases n is 1, and in other cases n is 0. In some embodiments, all atoms A, B, X, D, E, F are carbon (C). In some embodiments, one, two or three of the atoms A, B, X, D, E, F are nitrogen (N). According to some embodiments, at least one of the atoms A, B, X, D, B, F is substituted by one of the following: F, Cl, Br, I, alkyl, alkenyl, alkinyl, halogenated alkyl, halogenated alkenyl, cycloalkyl, O-alkyl, O-alkenyl, —NH-alkyl, —N(alkyl); —S-alkyl, —SO-alkyl, —SO-alkyl, nitro, cyano, carboxylester, phenyl, thiophenyl, benzyl, oxo, thio, hydroxy, mercapto, and imino, wherein at least one substituent is not oxo, thio, hydroxy, mercapto, imino, amino or methyl. According to yet other embodiments, one of the two atoms A or E is substituted by one of the following: F, Cl, Br, I, C₂-C₆-alkyl, alkenyl, alkinyl, halogenated alkyl, halogenated alkenyl, cycloalkyl, O-alkyl, O-alkenyl, —N-alkyl, —N(alkyl)₂; —S-alkyl, —SO-alkyl, —SO₂-alkyl, nitro, cyano, carboxylester, phenyl, thiophenyl, benzyl, or methyl, provided that if methyl then A, B, X, D, E, and F are all C.

In some embodiments formula I comprises a substituted pyrimidine, uracil, toluene, imidazole or pyrazole or triazole. According to other embodiments, formula I is selected from the following: 5-chloro-uracil, 5-bromo-uracil, 5-iodo-uracil, 5-ethyl-uracil, 5-propyl-uracil, 5-propinyl-uracil, (E)-5-(2-bromovinyl)-uracil, and 2.4-difluoro-toluene. According to one embodiment of the invention, formula I is fused with a 3- to-6-membered aromatic or aliphatic ring system. According to other embodiments, formula I is linked to a 5- to 6-membered sugar moiety, including a pentose or hexose. In some cases, the pentose is a furanose and hexose is a pyranose, which can optionally be substituted by F, amino, alkoxy, alkoxy-ethoxy, amonipropyl, alkenyl, alkinyl, or a O2,C4-alkylene bridge In other cases, the furanose is ribose or deoxyribose.

According to some embodiments of the invention, R₁ and R₂ are both L. In some embodiments, R₁ is L and R₂ is a nucleotide. Alternatively, in some cases R is a L and R₂ is a linkage, such that the oligonucleotide comprises a structure 5′ R₁CG 3′. Other embodiments include oligonucleotide wherein R₁ is L and R₂ is a linkage, and wherein a R₃ is 5′ to R₁YZ, such that the oligonucleotide comprises a structure 5′ R₃R₁YZ 3′. In some embodiments, R₁ is L and R₂ is a linkage, and wherein a second R₁ is 5′ to R₁YZ spaced by one nucleotide N, such that the oligonucleotide comprises a structure 5′ R₁NR₁YZ 3′. In some cases, the oligonucleotide may include two 5′ R₁NR₁YZ 3′ motifs.

According to some embodiments, The oligonucleotide includes Y that is one of the following pyrimidines: cytosine, 5-methyl-cytosine, 5-hydroxy-cytosine, 5-hydroxymethyl-cytosine, 5-halogeno-cytosine, 2-thio-cytosine, 4-thio-cytosine, N3-methyl-cytosine, N4-alkyl-cytosine or a 6-substituted cytosine.

According to some embodiments, the oligonucleotide includes Z that is a purine nucleotide including; guanine, 7-deaza-guanine, hypoxanthine, 7-deaza-hypoxanthine, 2-amino-purine, 4-thio-purine, 2.6-diamino-purine, 8-oxo-7.8-dihydroguanine, 7-thia-8-oxo-7.8-dihydroguanine, 7-allyl-8-oxo-7.8-dihydroguanine, 7-deaza-8-aza-guanine, 8-aza-guanine, N1-methyl-guanine or purine. In other embodiments, Z is a pyrimidine nucleotide, including T.

According to some embodiments of the invention, R₂ is L and R is a nucleotide.

According to some embodiments, the oligonucleotide is between 3-100 nucleotides in length; for example, the oligonucleotide is 3-6 nucleotides in length, 3-100 nucleotides in length, or 7-100 nucleotides in length. In some circumstances, the oligonucleotide is T-rich, such that at least 80% of the nucleotides are T.

The invention includes embodiments comprising at least one palindromic sequence. For example, in some cases, the oligonucleotide includes two palindromic sequences.

According to the invention, some embodiments include one to four unmethylated CG dinucleotides. In some embodiments, the oligonucleotide may include at least one (G)m sequence, wherein m is 4 to 10. In some cases, at least one but up to all CG dinucleotides are unmethylated. According to some embodiments, the oligonucleotide may additionally comprise a non-nucleotidic modification. The non-nucleotidic modifications include but are not limited to: C₆-C₄₈-polyethyleneglycol, C₃-C₂₀-alkane-diol, C₃-C₁₈-alkylamino linker, C₃-C₁₈-alkylthiol linker, cholesterol, bile acid, saturated or unsaturated fatty acid, folate, a hexadecyl-glycerol or dihexadecyl-glycerol group, an octadecyl-glycerol or dioctadecyl-glycerol group, a vitamin E group. In other embodiments, the oligonucleotide of the invention further comprises a non-nucleotidic brancher moiety or a nucleotidic brancher moiety. In some embodiments, the oligonucleotide includes a brancher moiety, wherein the oligonucleotides has at least two 5′-ends.

According to the invention, some embodiments include at least two nucleotides of the oligonucleotide have a stabilized linkage, including: phosphorothioate, phosphorodithioate, methylphosphonate, methylphosphonothioate boranophosphonate, phosphoramidate, or a dephospho linkage, either as enantiomeric mixture or as enantiomeric pure S- or R-configuration.

Yet in some embodiments, the YZ of R₁YZR₂ has a phosphodiester linkage or a phosphorothioate linkage. In some cases, the R₁Y and or the ZR₂ of R₁YZR₂ has a phosphorothioate linkage. In some embodiments, all other nucleotides have a phosphorothioate linkage.

According to some embodiments of the invention, the oligonucleotide is free of a microcarrier, including a lipid carrier.

According to the invention, the oligonucleotides may be an A class oligonucleotide, a B class oligonucleotide, a C class oligonucleotide, a P class oligonucleotide or a T class oligonucleotide. For the B class oligonucleotide of the invention, some embodiments include the sequence 5′ TCN₁TX₁X₂CGX₃X₄ 3′, wherein X₁ is G or A; X₂ is T, G, or A; X₃ is T or C and X₄ is T or C and N is any nucleotide, and N₁ and N₂ are nucleic acid sequences of about 0-25 N's each.

According to some embodiments of the invention, the oligonucleotide comprises at least one 3′-3′ linkage and or at least one 5′-5′ linkage.

In another aspect the invention is a composition of the oligonucleotides described herein in combination with an antigen or other therapeutic compound, such as an anti-microbial agent. The anti-microbial agent may be, for instance, an anti-viral agent, an anti-parasitic agent, an anti-bacterial agent or an anti-fungal agent.

A composition of a sustained release device including the oligonucleotides described herein is provided according to another aspect of the invention.

The composition may optionally include a pharmaceutical carrier and/or be formulated in a delivery device. In some embodiments the delivery device is selected from the group consisting of cationic lipids, cell permeating proteins, and sustained release devices. In one embodiment the sustained release device is a biodegradable polymer or a microparticle.

According to another aspect of the invention a method of stimulating an immune response is provided. The method involves administering an oligonucleotide to a subject in an amount effective to induce an immune response in the subject. Preferably the oligonucleotide is administered orally, locally, in a sustained release device, mucosally, systemically, parenterally, or intramuscularly. When the oligonucleotide is administered to the mucosal surface it may be delivered in an amount effective for inducing a mucosal immune response or a systemic immune response. In preferred embodiments the mucosal surface is selected from the group consisting of an oral, nasal, rectal, vaginal, and ocular surface.

In some embodiments the method includes exposing the subject to an antigen wherein the immune response is an antigen-specific immune response. In some embodiments the antigen is selected from the group consisting of a tumor antigen, a viral antigen, a bacterial antigen, a parasitic antigen and a peptide antigen.

The oligonucleotides are useful for treating cancer in a subject having cancer or in a subject at risk of developing a cancer (e.g., reducing a risk of developing cancer). The cancer may be selected from the group consisting of biliary tract cancer, breast cancer, cervical cancer, choriocarcinoma, colon cancer, endometrial cancer, gastric cancer, intraepithelial neoplasms, lymphomas, liver cancer, lung cancer (e.g. small cell and non-small cell), melanoma, neuroblastomas, oral cancer, ovarian cancer, pancreatic cancer, prostate cancer, rectal cancer, sarcomas, thyroid cancer, and renal cancer, as well as other carcinomas and sarcomas. In some important embodiments, the cancer is selected from the group consisting of bone cancer, brain and CNS cancer, connective tissue cancer, esophageal cancer, eye cancer, Hodgkin's lymphoma, larynx cancer, oral cavity cancer, skin cancer, and testicular cancer.

The oligonucleotides may also be used for increasing the responsiveness of a cancer cell to a cancer therapy (e.g., an anti-cancer therapy), optionally when the CpG immunostimulatory oligonucleotide is administered in conjunction with an anti-cancer therapy. The anti-cancer therapy may be a chemotherapy, a vaccine (e.g., an in vitro primed dendritic cell vaccine or a cancer antigen vaccine) or an antibody based therapy. This latter therapy may also involve administering an antibody specific for a cell surface antigen of for example, a cancer cell, wherein the immune response results in antibody dependent cellular cytotoxicity (ADCC). In one embodiment, the antibody may be selected from the group consisting of Ributaxin, Herceptin, Quadramet, Panorex, IDEC-Y2B8, BEC2, C225, Oncolym, SMART M195, ATRAGEN, Ovarex, Bexxar, LDP-03, ior t6, MDX-210, MDX-11, MDX-22, OV103, 3622W94, anti-VEGF, Zenapax, MDX-220. MDX-447, MELIMMUNE-2, MELIMMUNE-1, CEACIDE, Pretarget, NovoMAb-G2, TNT, Gliomab-H, GNI-250, EMD-72000, LymphoCide, CMA 676, Monopharm-C, 4B5, ior egf.r3, ior c5, BABS, anti-FLK-2, MDX-260, ANA Ab, SMART 1D10 Ab, SMART ABL 364 Ab and ImmuRAIT-CEA.

Thus, according to some aspects of the invention, a subject having cancer or at risk of having a cancer is administered an oligonucleotide and an anti-cancer therapy. In some embodiments, the anti-cancer therapy is selected from the group consisting of a chemotherapeutic agent, an immunotherapeutic agent and a cancer vaccine.

The invention in other aspects relates to methods for preventing disease in a subject. The method involves administering to the subject an oligonucleotide on a regular basis to promote immune system responsiveness to prevent disease in the subject. Examples of diseases or conditions sought to be prevented using the prophylactic methods of the invention include microbial infections (e.g., sexually transmitted diseases) and anaphylactic shock from food allergies.

In other aspects, the invention is a method for inducing an innate immune response by administering to the subject an oligonucleotide in an amount effective for activating an innate immune response.

According to another aspect of the invention a method for treating a viral or retroviral infection is provided. The method involves administering to a subject having or at risk of having a viral or retroviral infection, an effective amount for treating the viral or retroviral infection of any of the compositions of the invention. In some embodiments the virus is caused by a hepatitis virus e.g., hepatitis B, hepatitis C, HIV, herpes virus, or papillomavirus.

A method for treating a bacterial infection is provided according to another aspect of the invention. The method involves administering to a subject having or at risk of having a bacterial infection, an effective amount for treating the bacterial infection of any of the compositions of the invention. In one embodiment the bacterial infection is due to an intracellular bacteria.

In another aspect the invention is a method for treating a parasite infection by administering to a subject having or at risk of having a parasite infection, an effective amount for treating the parasite infection of any of the compositions of the invention. In one embodiment the parasite infection is due to an intracellular parasite. In another embodiment the parasite infection is due to a non-helminthic parasite.

In some embodiments the subject is a human and in other embodiments the subject is a non-human vertebrate selected from the group consisting of a dog, cat, horse, cow, pig, turkey, goat, fish, monkey, chicken, rat, mouse, and sheep.

In another aspect, the invention relates to a method for treating autoimmune disease by administering to a subject having or at risk of having an autoimmune disease an effective amount for treating or preventing the autoimmune disease of any of the compositions of the invention.

The invention in some aspects is a method for treating airway remodeling, asthma or allergy comprising: administering to a subject any of the compositions of the invention, in an effective amount to treat airway remodeling asthma or allergy in the subject. In one embodiment the subject has asthma, chronic obstructive pulmonary disease, or is a smoker. In other embodiments the subject is free of symptoms of asthma.

Use of an oligonucleotide of the invention for stimulating an immune response is also provided as an aspect of the invention.

A method for manufacturing a medicament of an oligonucleotide of the invention for stimulating an immune response is also provided.

Each of the limitations of the invention can encompass various embodiments of the invention. It is, therefore, anticipated that each of the limitations of the invention involving any one element or combinations of elements can be included in each aspect of the invention. This invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having,” “containing”, “involving”, and variations thereof herein, is meant to encompass the items listed thereafter and equivalents thereof as well as additional items.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A and 1B are two drawings illustrating the structure of the modified bases of the invention. FIG. 1A shows a section of a CpG hexamer motif (GTCGTT). FIG. 1B shows the incorporated hydrophobic shape analogs of 2′-deoxythymidine: 2,4-Difluorotoluene (FF), 5-bromouridine (BU) and 5-iodouridine (JU).

FIG. 2 is a graph showing results of a luciferase assay with B-class oligonucleotides (ODN) modified with thymine shape analog 2,4-difluorotoluene (FF). The activity of FF-modified ODN (SEQ ID NO:3-9) was compared to that of the unmodified B-class parent sequence (SEQ ID NO:1), fully PS parent sequence (SEQ ID NO:2), and a third unmodified B-class ODN (SEQ ID NO:37). hTLR9-LUC-293 cells were stimulated with indicated amounts of ODN and NF-kB stimulation was determined by measuring luciferase activity 16 h later. The x-axis is log ODN concentration in μM and the y-axis is the relative stimulation index.

FIG. 3 is a graph demonstrating the results of a luciferase assay with modified B-class ODN. Thymidine (T) was substituted with 5-bromo-2′-deoxyuridine (BU) (SEQ ID NO:10-12) and 5-iodo-2′-deoxyuridine (JU) (SEQ ID NO:13-15). Their activity was compared to that of the unmodified B-class parent sequence (SEQ ID NO:1), fully PS parent sequence (SEQ ID NO:2), and a third unmodified B-class ODN (SEQ ID NO:37). hTLR9-LUC-293 cells were stimulated with indicated amounts of ODN and NF-κB stimulation was determined by measuring Luciferase activity 16 h later. The x-axis is log ODN concentration in μM and the y-axis is the relative stimulation index.

FIG. 4 is a graph demonstrating the results of a luciferase assay with modified B-class ODN. 2′-deoxythymidine (T) was substituted with 2′-deoxyuridine (U) (SEQ ID NO:16-18). The activity of the U-modified ODN was compared to that of the unmodified B-class parent sequence (SEQ ID NO:1), fully PS parent sequence (SEQ ID NO:2), and a third unmodified B-class ODN (SEQ ID NO:37). hTLR9-LUC-293 cells were stimulated with indicated amounts of ODN and NF-κB stimulation was determined by measuring Luciferase activity 16 h later. The x-axis is log ODN concentration in μM and the y-axis is the relative stimulation index.

FIG. 5 is two graphs demonstrating the results of a luciferase assay and a PBMC assay with modified B class ODN. The relative activity of an ODN with 5-Ethyl-2′-deoxyuridine (EU) (SEQ ID NO:42), 2′-deoxyuridine (U) (SEQ ID NO:16), 5-iodo-2′-deoxyuridine (JU) (SEQ ID NO:13), 5-bromo-2′-deoxyuridine (BU) (SEQ ID NO:10), and 5-Chloro-2′-deoxyuridine (CU) (SEQ ID NO:41) was compared to that of the parent sequence (SEQ ID NO:1). FIG. 5a shows TLR9 activity and FIG. 5b shows IFN-alpha production. Shown is the mean+/−SEM of three donors. The x-axes are ODN concentration in μM and the y-axes are the relative stimulation index (FIG. 5a ) or IFN-alpha concentration in pg/ml (FIG. 5b ).

FIG. 6 is a graph demonstrating the results of a luciferase assay with EU-modified ODN. The activity of EU-modified ODN SEQ ID NO:29, 30, and 42 was compared to that of the parent sequence (SEQ ID NO:1) and another unmodified B-class ODN (SEQ ID NO:37). The x-axis is ODN concentration in μM and the y-axis is the relative stimulation index.

FIG. 7 is a graph demonstrating the results of a luciferase assay with modified B class ODN. The activity of JU-modified SEQ ID NO:19-24 was compared to that of parent sequence SEQ ID NO:37. The x-axis is ODN concentration in μM and the y-axis is the relative stimulation index.

FIG. 8 is two graphs demonstrating the results of a luciferase assay and a PBMC assay with modified A class ODN. The activity of JU-modified SEQ ID NO:35-37 was compared to that of the unmodified parent sequence (SEQ ID NO:43) and to unmodified B-class ODN SEQ ID NO: 1. FIG. 8a shows TLR9 activity and FIG. 8b shows IFN-alpha production. Shown is the mean+/−SEM of three donors. The x-axes are log ODN concentration (FIG. 8a ) or ODN concentration (FIG. 8b ) in μM and the y-axes are the relative stimulation index (FIG. 8a ) or IFN-alpha concentration in pg/ml (FIG. 8b ).

FIG. 9 is a graph demonstrating the results of a luciferase assay with modified C class ODN. The activity of JU-modified C-class ODN SEQ ID NO:27-28 and 44-45 was compared to that of the unmodified parent sequence SEQ ID NO:45 and to an unmodified B-class ODN (SEQ ID NO:37). The x-axis is ODN concentration in μM and the y-axis is the relative stimulation index.

FIG. 10 is a graph demonstrating the results of a luciferase assay with modified P class ODN. The activity of JU-modified SEQ ID NO:31-33 was compared to that of the unmodified parent sequence (SEQ ID NO:52). The x-axis is log ODN concentration in μM and the y-axis is the relative stimulation index.

FIG. 11 is a graph demonstrating the results of a luciferase assay with modified T class ODN. The activity of JU-modified SEQ ID NO:47-50 and U-modified SEQ ID NO:51 was compared to that of unmodified parent sequence SEQ ID NO:25. The x-axis is log ODN concentration in μM and the y-axis is the relative stimulation index.

FIGS. 12a-b are graphs demonstrating the results of a luciferase assay with short ODN. The activity of JU-modified short ODN SEQ ID NO:39-40 was compared to that of the unmodified parent sequence SEQ ID NO:38 and to the B-class ODN SEQ ID NO:37. ODN were formulated with and without DOTAP. The x-axis is log ODN concentration in μM and the y-axis is the relative stimulation index.

FIG. 13 is four graphs showing the results of an ELISA assay measuring cytokine concentration in splenocyte culture supernatants where BALB/c mouse splenocytes were cultured with different ODNs. Culture supernatants were harvested at 6 hr (for TNF-alpha) or 24 hr (for IL-6, IL-10 and IL-12). The activities of a JU-modified B-class ODN (SEQ ID NO: 13), an unmodified B-class ODN (SEQ ID NO:37), and a non-CpG negative control ODN (SEQ ID NO:26) were compared. FIGS. 13a-d show TNF-alpha, IL-6, IL-10, and IL-12 concentration, respectively. The x-axes are ODN concentration in μg/ml and the y-axes are cytokine concentration in pg/ml.

FIG. 14 is a graph showing the results of FACS analysis of B cell proliferation. CPSE stained BALB/c mouse splenocytes (4×10⁵/well) were incubated with 0.001, 0.01, 0.1, 0.3, 1, 3 or 10 μg/ml of ODN. At 72 hours post incubation, cells were stained for CD19 and B-cell proliferation was determined by FACS followed by analysis by ModFit Software. The activities of a JU-modified B-class ODN (SEQ ID NO:13), an unmodified B-class ODN (SEQ ID NO:37), and a non-CpG negative control ODN (SEQ ID NO:26) were compared. The x-axis is ODN concentration in μg/ml and the y-axis is relative B cell proliferation.

FIG. 15 is two graphs showing in vivo cytokine production as measured by ELISA. BALB/c mice (5 per group) were injected SC with 10, 50 or 100 μg of ODN. Control group received 100 μl of PBS alone. Animals were bled by cardiac puncture at 1 hour (for TNF-alpha) or 3 hour (for IP-10) post injection and plasma assayed for TNF-alpha and IP-10 by ELISA. The activities of a JU-modified B-class ODN (SEQ ID NO:13) and an unmodified B-class ODN (SEQ ID NO:37) were compared. FIG. 15a shows TNF-alpha concentration and FIG. 15b shows IP-10 concentration. The x-axes are ODN dose in μg and the y-axes are cytokine concentration in pg/ml.

FIG. 16 is a graph showing TLR9-mediated NF-κB activation by a B-class ODN with a universal base (6-nitrobenzimidazol) (SEQ ID NO:178) in place of thymidine in the parent sequence (SEQ ID NO:1). hTLR9-LUC-293 cells were incubated with indicated amounts of nucleic acids and NF-κB activation was determined 16 h later by measuring luciferase activity. The x-axis is log of ODN concentration in μM and the y-axis is IFN-α concentration in pg/ml.

FIG. 17 is a graph showing TLR9-mediated NF-κB activation by B-class ODN with 5-(2-bromovinyl)-uridine (SEQ ID NO:153 and 154) in place of thymine in the parent sequence (SEQ ID NO:1). hTLR9-LUC-293 cells were incubated with indicated amounts of nucleic acids and NF-κB activation was determined 16 h later by measuring luciferase activity. The x-axis is log of ODN concentration in μM and the y-axis is IFN-α concentration in pg/ml.

FIG. 18 is a graph showing TLR9-mediated NF-κB activation by B-class ODN with a sugar modification (2′-O-methylguanosine) in addition to a lipophilic substituted nucleotide analog (SEQ ID NO:111-113). The activity of these ODN was compared to that of the parent sequence (SEQ ID NO:1) and the same sequence with a lipophilic substituted nucleotide analog only (SEQ ID NO:13). hTLR9-LUC-293 cells were incubated with indicated amounts of nucleic acids and NF-κB activation was determined 16 h later by measuring luciferase activity. The x-axis is log of ODN concentration in μM and the y-axis is IFN-α concentration in pg/ml.

FIG. 19 is a graph showing TLR9-mediated NF-κB activation by ranched B-class ODN with multiple 5′ accessible ends. The activity of the branched ODN (SEQ ID NO:96, 97, 101, and 102) was compared to that of SEQ ID NO:1. hTLR9-LUC-293 cells were incubated with indicated amounts of nucleic acids and NF-κB activation was determined 16 h later by measuring luciferase activity. The x-axis is log of ODN concentration in μM and the y-axis is IFN-α concentration in pg/ml.

FIG. 20 is a graph showing TLR9-mediated NF-κB activation by a short unmodified B-class ODN (SEQ ID NO:38) and an ODN of the same sequence with a lipophilic substituted nucleotide analog and a lipophilic 3′ tag (SEQ ID NO:126). Both were formulated with and without DOTAP. hTLR9-LUC-293 cells were incubated with indicated amounts of nucleic acids and NF-κB activation was determined 16 h later by measuring luciferase activity. The x-axis is log of ODN concentration in μM and the y-axis is IFN-α concentration in pg/ml.

FIG. 21 is a graph showing TLR9-mediated NF-κB activation by two B-class ODN with 5-proynyl-dU (SEQ ID NO:116 and 117) in place of thymine of the parent sequence (SEQ ID NO:1). hTLR9-LUC-293 cells were incubated with indicated amounts of nucleic acids and NF-κB activation was determined 16 h later by measuring luciferase activity. The x-axis is log of ODN concentration in μM and the y-axis is IFN-α concentration in pg/ml.

FIG. 22 is a graph showing hTLR9-mediated NF-κB activation by B-class ODN with a second nucleotide analog in addition to a lipophilic substituted nucleotide analog (SEQ ID NO:138, 7-deaza-dG; SEQ ID NO:139, inosine; SEQ ID NO:140, 5-methyl-dC). The activity of these ODN was compared to that of the parent sequence (SEQ ID NO:1) and the same sequence with a lipophilic substituted nucleotide analog only (SEQ ID NO:13). hTLR9-LUC-293 cells were incubated with indicated amounts of nucleic acids and NF-κB activation was determined 16 h later by measuring luciferase activity. The x-axis is log of ODN concentration in μM and the y-axis is IFN-α concentration in pg/ml.

FIG. 23 is a graph showing hTLR9-mediated NF-κB activation by T-class ODN with a lipophilic substituted nucleotide analog (SEQ ID NO:132-134). The activity of these was compared to that of an immunostimulatory C-class ODN (SEQ ID NO:198). hTLR9-LUC-293 cells were incubated with indicated amounts of nucleic acids and NF-κB activation was determined 16 h later by measuring luciferase activity. The x-axis is log of ODN concentration in μM and the y-axis is IFN-α concentration in pg/ml.

FIG. 24 is two graphs showing hTLR9-mediated NF-κB activation by P-class ODN with a lipophilic substituted nucleotide analog (SEQ ID NO:58-63). FIG. 24a shows the activity of SEQ ID NO:58-61 compared to that of a B-class positive control (SEQ ID NO:55) and an unmodified P-class ODN (SEQ ID NO:56). FIG. 24b shows the activity of SEQ ID NO:62-63 compared to that of the same positive and negative controls. hTLR9-LUC-293 cells were incubated with indicated amounts of nucleic acids and NF-κB activation was determined 16 h later by measuring luciferase activity. The x-axis is log of ODN concentration in μM and the y-axis is the relative stimulation index.

FIG. 25 is a graph showing hTLR9-mediated NF-κB activation by P-class ODN with a lipophilic substituted nucleotide analog (SEQ ID NO:64, 66-67). The activity of these is compared to that of a B-class positive control (SEQ ID NO:55), a C-class ODN (SEQ ID NO:68) and an unmodified P-class ODN (SEQ ID NO:57). hTLR9-LUC-293 cells were incubated with indicated amounts of nucleic acids and NF-κB activation was determined 16 h later by measuring luciferase activity. The x-axis is log of ODN concentration in μM and the y-axis is the relative stimulation index.

FIG. 26 is two graphs showing induction of IFN-α by P-class ODN with a lipophilic substituted nucleotide analog (SEQ ID NO:58-63). FIG. 26a shows the activity of SEQ ID NO:58-61 compared to that of a B-class positive control (SEQ ID NO:55) and an unmodified P-class ODN (SEQ ID NO:56). FIG. 26b shows the activity of SEQ ID NO:62-63 compared to that of the same positive and negative controls. Human PBMC were incubated with the indicated ODN for 48 hours. IFN-α was then determined in the cell culture supernatants by ELISA. The x-axes are ODN concentration in μM and the y-axes are IFN-α concentration in pg/ml.

FIG. 27 is a graph showing induction of IFN-α by P-class ODN with a lipophilic substituted nucleotide analog (SEQ ID NO:64, 66-67). The activity of these is compared to that of a B-class positive control (SEQ ID NO:55), a C-class ODN (SEQ ID NO:68) and an unmodified P-class ODN (SEQ ID NO:57). Human PBMC were incubated with the indicated ODN for 48 hours. IFN-α was then determined in the cell culture supernatants by ELISA. The x-axes are ODN concentration in μM and the y-axes are IFN-α concentration in pg/ml.

FIG. 28 is two graphs showing IL-6 induction by P-class ODN with a lipophilic substituted nucleotide analog (SEQ ID NO:58, 60-62, FIG. 28a ) (SEQ ID NO:64 and 67, FIG. 28b ). The activity was compared to that of an unmodified B-class ODN (SEQ ID NO:55), and unmodified C-class ODN (SEQ ID NO:54), a negative control ODN (SEQ ID NO:53), and an unmodified P-class ODN (SEQ ID NO:56). PBMC from three donors were incubated with the ODN for 24 hours and the supernatants were analyzed by luminex. Shown is the mean+/−SEM. The x-axes are ODN concentration in μM and the y-axes are IL-6 concentration in pg/ml.

FIG. 29 is two graphs showing B-cell proliferation after treatment with P-class class ODN with a lipophilic substituted nucleotide analog (SEQ ID NO:58, 60-62, FIG. 29a ) (SEQ ID NO:64 and 67, FIG. 29b ). The activity was compared to that of an unmodified B-class ODN (SEQ ID NO:55), an unmodified C-class ODN (SEQ ID NO:54), a negative control ODN (SEQ ID NO:53), an unmodified P-class ODN (SEQ ID NO:56), LPS, R-848, SEB, and a poly[I]:[C] ODN. CFSE-labeled PBMC from three donors were incubated with the ODN for 5 days and then stained with a CD19 antibody. The percentage of B cells with reduced CFSE staining was determined. The x-axes are ODN concentration in μM and the y-axes are % of B cells with reduced staining after division.

FIG. 30 is a graph showing induction of murine IFN-α by P-class ODN with a lipophilic substituted nucleotide analog (SEQ ID NO:58, 60-62, 64, and 67). The activity of these is compared to that of a B-class positive control (SEQ ID NO:55) and a negative control (SEQ ID NO:26). BALB/c mice (5 per group) were injected SC with differing doses of ODN. Animals were bled at 3 hr post injection and plasma tested for IFN-alpha by ELISA. The x axis is ODN dose in μg and the y-axis is IFN-α concentration in pg/ml.

FIG. 31 is two graphs showing the effect of ODN on tumor volume in the mouse SA1N tumor model. Female A/J mice (10 per group) were injected SC with 5×10 SaI/N tumor cells on day 0. Mice were treated with 35 μg (FIG. 31a ) or 100 μg (FIG. 31b ) P-class ODN with a lipophilic substituted nucleotide analog (SEQ ID NO:60, 64, and 67), an unmodified C-class ODN, an unmodified B-class ODN (SEQ ID NO:55), or PBS alone given SC once weekly starting on day 8 post tumor induction. Animals were monitored for survival and tumor volume. Tumor size (the length and the width) was measured using a digital vernier caliper. Tumor volume was calculated by using the formula: Tumor volume=(0.4)(ab2), where a=large diameter and b=smaller diameter. The x-axes show days post tumor induction and the y-axes show tumor volume in mm³.

DETAILED DESCRIPTION

The invention is based in part on CpG oligonucleotides that show enhanced immunostimulatory capacity. CpG oligonucleotides are known to stimulate the immune system, for example through interaction with toll-like receptor 9 (TLR9). Stimulation of TLR9 has many effects including stimulation of a Th1 biased immune response, NK cell activation and B cell activation. The invention is related in some aspects to the identification of immunostimulatory oligonucleotides with altered structure that affects their interaction with TLR9. It was discovered by the inventors that oligonucleotides with lipophilic substituted nucleotide analogs outside the CpG motif have enhanced ability to stimulate interferon-α (IFN-α) production and induce TLR9 activation. This effect has been observed in all classes of immunostimulatory oligonucleotides tested. These modified oligonucleotides with enhanced stimulatory capacity have been termed B class oligonucleotides.

The E class modified oligonucleotides of the instant invention have in some instances enhanced capacity for inducing an immune response. An induction of an immune response refers to any increase in number or activity of an immune cell, or an increase in expression or absolute levels of an immune factor, such as a cytokine. Immune cells include, but are not limited to, NK cells, CD4+ T lymphocytes, CD8+ T lymphocytes, B cells, dendritic cells, macrophage and other antigen-presenting cells. Cytokines include, but are not limited to, interleukins, TNF-α, IFN-α,β and γ, Flt-ligand, and co-stimulatory molecules.

It is known that oligonucleotides containing unmethylated CpG motifs are able to stimulate immune responses through the Toll-like receptor 9 (TLR9) pathway. The induction of many cytokines correlates with TLR9 activation. Thus induction increases a TLR9 stimulation increases. However there is generally an inverse correlation between TLR9 and IFN-α induction for CpG ODN. It was discovered that some of the modifications of the invention can produce a modified signaling pattern such that a more direct correlation, rather than an inverse correlation between TLR9 activation and IFN-α is observed.

The inventors set out to investigate the impact of the lipophilic residues in region surrounding the CpG motif. As described in the examples below several different types of lipophilic substituted nucleotide analogs, such as 2,4-difluorotoluene, 5-bromouracil and 5-iodouracil were incorporated into a CpG oligonucleotide on either the 5′ or 3′ side of the CpG motif Unexpectedly, incorporation of these lipophilic substituted nucleotide analogs led to an unusually strong increase in hTLR9 activity as well as IFN-α induction in human PBMC's Substitution with a non-lipophilic nucleotide such as a uracil residue (which is structurally similar to a thymine but lacking a methyl group) produced a strong decrease in hTLR9 stimulation. In the oligonucleotides tested, the increase in TLR9 stimulation appeared to be better if the lipophilic substituted nucleotide analog is positioned 5′ to the CpG motif than when it was positioned 3′ to the motif. Double substitution (i.e. a 5′ and 3′ lipophilic substituted nucleotide analog substitution) resulted in most potent stimulation of those tested. In contrast, substitution of guanin or cytosine by 2,4-difluorotoluene at the CpG motif led in both cases to a strong decrease of the TLR9 stimulation index.

The lipophilic substituted nucleotide analogs modification resulted in a strong enhancement of IFN-α induction. Especially, for the 5-bromouracil and 5-iodouracil modified ODN, there appeared to be a good correlation between TLR9 stimulation and IFN-α induction. As mentioned above, this observation was unexpected, since (i) the parent molecule 21317 is virtually inactive in inducing IFN-α and (ii) there is usually an inverse correlation between TLR9 and IFN-α induction for CpG ODN which do not contain these modifications.

In some aspects of the invention the oligonucleotide has the sequence R₁YZR₂. The olignucleotide may be include one or more such motifs. R₁ and R₂ are independently any one of lipophilic substituted nucleotide analog (L), a nucleotide, or a linkage. It is preferred, however, that at least one of R₁ and R₂ is a lipophilic substituted nucleotide analog (L). In some instances R₁ and R₂ are both L. As shown in the examples section below oligonucleotides having an L both 5′ and 3′ to the CpG motif were particularly stimulatory. However sometimes only one R is an L. For instance R₁ may be L and R₂ is a nucleotide or vice versa. Alternatively R₁ may be a L and R₂ may be a linkage, such that the oligonucleotide comprises a structure 5′ R₁CG 3′.

In some instances the oligonucleotide has the sequence R₁N₁YZN₂R₂ wherein N₁ and N₂ are nucleotides of 0-3 nucleotides in length. Other possible variations include structures such as 5′ R₁N₁R₁YZ N₂ 3′, 5′ R₃R₁YZ 3 and R₁ZN₂R₂.

Y is a pyrimidine nucleotide. Z is a purine, a pyrimidine, or an abasic residue. In some embodiments Z is preferably a purine.

L is a lipophilic substituted nucleotide analog which may be, for instance, a 5- or 6-membered ring nucleobase analog. An example of a 5- or 6-membered ring nucleobase analog is shown in the following group of formula I.

A, B, X, D, E, and F are independently any one of C (carbon) or N (nitrogen) optionally bearing hydrogen or a substituent such as for instance, but not limited to, F, Cl, Br, I, alkyl, alkenyl, alkinyl, halogenated alkyl, halogenated alkenyl, cycloalkyl, O-alkyl, O-alkenyl, —NH-alkyl, —N(alkyl)₂; —S-alkyl, —SO-alkyl, —SO₂-alkyl, nitro, cyano, carboxylester, phenyl, thiophenyl, benzyl, oxo, thio, hydroxy, mercapto, and imino. In some instances, at least one substituent is not oxo, thio, hydroxy, mercapto, imino, amino or methyl. n is 0 or 1. The dotted lines indicate optional double bonds. However, at least one substituent is not chosen from the group consisting of oxo, thio, hydroxy, mercapto, imino, amino, methyl and hydrogen. Additionally the total of A, B, X, D, B and P atoms is not more than 3 nitrogens (N). In some embodiments all atoms A, B, X, D, B, F are carbon (C). Alternatively, at least one, two, or three of the atoms A, B, X, D, B, F is nitrogen (N).

The compound of formula may be, for example, any of the following lipophilic substituted nucleotide analogs: a substituted pyrimidine, a substituted uracil, a substituted toluene, a substituted imidazole or pyrazole, a substituted triazole, 5-chloro-uracil, 5-bromo-uracil, 5-iodo-uracil, 5-ethyl-uracil, 5-propyl-uracil, 5-propinyl-uracil, (E)-5-(2-bromovinyl)-uracil, or 2.4-difluoro-toluene.

The lipophilic substituted nucleotide analog may be separate or it may be fused with another compound. For instance is may be fused to a 3- to-6-membered aromatic or aliphatic ring system. It may also be linked to a 5- to 6-membered sugar moiety such as for instance a pentose or hexose. An example of a pentose is a furanose such as a ribose or deoxyribose and an example of a hexose is a pyranose. The pentose or hexose can optionally be substituted by F, amino, alkoxy, alkoxy-ethoxy, amonipropyl, alkenyl, alkinyl, or a O2,C4-alkylene bridge.

The oligonucleotide may also include a non-nucleotidic modification such as a C₆-C₄₈-polyethyleneglycol, C₃-C₂₀-alkane-diol, C₃-C₁₈-alkylamino linker, C₃-C₁₈-alkylthiol linker, cholesterol, bile acid, saturated or unsaturated fatty acid, folate, hexadecyl-glycerol, dihexadecyl-glycerol group, an octadecyl-glycerol or dioctadecyl-glycerol group or a vitamin E group.

The lipophilic substituted nucleotide analogs can be incorporated into any immunostimulatory oligonucleotide. In some embodiments of the invention the immunostimulatory oligonucleotides include immunostimulatory motifs which are “CpG dinucleotides”. A CpG dinucleotide can be methylated or unmethylated. An immunostimulatory nucleic acid containing at least one unmethylated CpG dinucleotide is a nucleic acid molecule which contains an unmethylated cytosine-guanine dinucleotide sequence (i.e., an unmethylated 5′ cytidine followed by 3′ guanosine and linked by a phosphate bond) and which activates the immune system; such an immunostimulatory nucleic acid is a CpG nucleic acid. CpG nucleic acids have been described in a number of issued patents, published patent applications, and other publications, including U.S. Pat. Nos. 6,194,388; 6,207,646; 6,214,806; 6,218,371; 6,239,116; and 6,339,068. An immunostimulatory nucleic acid containing at least one methylated CpG dinucleotide is a nucleic acid which contains a methylated cytosine-guanine dinucleotide sequence (i.e., a methylated 5′ cytidine followed by a 3′ guanosine and linked by a phosphate bond) and which activates the immune system. In other embodiments the immunostimulatory oligonucleotides are free of CpG dinucleotides. These oligonucleotides which are free of CpG dinucleotides we referred to as non-CpG oligonucleotides, and they have non-CpG immunostimulatory motifs. Preferably these are T-rich ODN, such as ODN having at least 80% T.

The E class ODNs of the invention may include motifs and properties of other CpG ODN classes such as A class, B call, C class, T class and P class as long as they include lipophilic substituted nucleotide analogs 5′ and/or 3′ of a YGZ motif.

“A class” CpG immunostimulatory nucleic acids have been described in U.S. Non-Provisional patent application Ser. No. 09/672,126 and published PCT application PCT/US00/26527 (WO 01/22990), both filed on Sep. 27, 2000. These nucleic acids are characterized by the ability to induce high levels of interferon-alpha while having minimal effects on B cell activation. The A class CpG immunostimulatory nucleic acid do not necessarily contain a hexamer palindrome GACGTC, AGCGCT, or AACGTT described by Yamamoto and colleagues. Yamamoto S et al. J Immunol 148:4072-6 (1992).

Exemplary sequences of A class immunostimulatory nucleic acids are described in U.S. Non-Provisional patent application Ser. No. 09/672,126 and published PCT application PCT/US00/26527 (WO 01/22990), both filed on Sep. 27, 2000.

“B class” ODN are potent at activating B cells but we relatively weak in inducing IFN-α and NK cell activation. The B class CpG nucleic acids typically are fully stabilized and include an unmethylated CpG dinucleotide within certain preferred base contexts. See, e.g., U.S. Pat. Nos. 6,194,388; 6,207,646; 6,214,806; 6,218,371; 6,239,116; and 6,339,068. Another class is potent for inducing IFN-α and NK cell activation but is relatively weak at stimulating B cells; this class has been termed the “A class”. The A class CpG nucleic acids typically have stabilized poly-G sequences at 5′ and 3′ ends and a palindromic phosphodiester CpG dinucleotide-containing sequence of at least 6 nucleotides. See, for example, published patent application PCT/US00/26527

Yet another class of CpG nucleic acids activates B cells and NK cells and induces IFN-α; this class has been termed the C-class. The “C class” immunostimulatory nucleic acids contain at least two distinct motifs have unique and desirable stimulatory effects on cells of the immune system. Some of these ODN have both a traditional “stimulatory” CpG sequence and a “GC-rich” or “B-cell neutralizing” motif. These combination motif nucleic acids have immune stimulating effects that fall somewhere between those effects associated with traditional “class B” CpG ODN, which are strong inducers of B cell activation and dendritic cell (DC) activation, and those effects associated with a more recently described class of immune stimulatory nucleic acids (“class A” CpG ODN) which are strong inducers of IFN-α and natural killer (NK) cell activation but relatively poor inducers of B-cell and DC activation. Krieg A M et al. (1995) Nature 374:546-9; Ballas Z K et al. (1996) J Immunol 157:1840-5; Yamamoto S et al. (1992) J Immunol 148:4072-6. While preferred class B CpG ODN often have phosphorothioate backbones and preferred class A CpG ODN have mixed or chimeric backbones, the C class of combination motif immune stimulatory nucleic acids may have either stabilized, e.g., phosphorothioate, chimeric, or phosphodiester backbones, and in some preferred embodiments, they have semi-soft backbones. This class has been described in U.S. patent application U.S. Ser. No. 10/224,523 filed on Aug. 19, 2002, the entire contents of which is incorporated herein by reference.

The “P class” immunostimulatory oligonucleotides have several domains, including a 5′TLR activation domain, 2 duplex forming regions and an optional spacer and 3′ tail. This class of oligonucleotides has the ability in some instances to induce much higher levels of IFN-α secretion than the C-Class. The P-Class oligonucleotides have the ability to spontaneously self-assemble into concatamers either in vitro and/or in vivo. Without being bound by any particular theory for the method of action of these molecules, one potential hypothesis is that this property endows the P-Class oligonucleotides with the ability to more highly crosslink TLR9 inside certain immune cells, inducing a distinct pattern of immune activation compared to the previously described classes of CpG oligonucleotides. Cross-linking of TLR9 receptors may induce activation of stronger IFN-α secretion through the type I IFNR feedback loop in plasmacytoid dendritic cells. P class oligonucleotides are described at least in U.S. application Ser. No. 11/706,561.

The “T class” oligonucleotides induce secretion of lower levels of IFN-alpha when not modified as in the ODNs of the invention and IFN-related cytokines and chemokines than B class or C class oligonucleotides, while retaining the ability to induce levels of IL-10 similar to B class oligonucleotides. T class oligonucleotides are described at least in U.S. patent application Ser. No. 11/099,683, the entire contents of which are hereby incorporated by reference.

In one embodiment the immunostimulatory ODN of the invention is advantageously combined with a cationic lipid. In one embodiment the cationic lipid is DOTAP (N-[1-(2,3-dioleoyloxy)propy-1]-N,N,N-trimethylammonium methyl-sulfate). Other agents with similar properties including trafficking to the endosomal compartment can be used in place of or in addition to DOTAP. Other lipid formulations include, for example, as EFFECTENE™ (a non-liposomal lipid with a special DNA condensing enhancer) and SUPERFECT™ (a novel acting dendrimeric technology). Liposomes are commercially available from Gibco BRL, for example, as LIPOFECTIN™ and LIPOFECTACE™, which are formed of cationic lipids such as N-[1-(2,3 dioleyloxy)-propyl]-N,N,N-trimethylammonium chloride (DOTMA) and dimethyl dioctadecylammonium bromide (DDAB). Methods for making liposomes are well known in the art and have been described in many publications. Liposomes also have been reviewed by Gregoriadis G (1985) Trends Biotechnol 3:235-241.

In other embodiments the immunostimulatory ODN are not formulated in cationic liposomes. Due to the lipophilic nature of the modified analogs within the ODN even short ODN such as 3 nucleotides in length may not require formulation to efficiently function in vivo.

In one embodiment the immunostimulatory ODN of the invention are in the form of covalently closed, dumbbell-shaped molecules with both primary and secondary structure. In one embodiment such cyclic oligoribonucleotides include two single-stranded loops connected by an intervening double-stranded segment. In one embodiment at least one single-stranded loop includes an immunostimulatory DNA motif of the invention. Other covalently closed, dumbbell-shaped molecules of the invention include chimeric DNA:RNA molecules in which, for example, the double-stranded segment is at least partially DNA (e.g., either homodimeric dsDNA or heterodimeric DNA:RNA) and at least one single-stranded loop includes an immunostimulatory DNA motif of the invention. Alternatively, the double stranded segment of the chimeric molecule is DNA.

In certain embodiments the immunostimulatory ODN is isolated. An isolated molecule is a molecule that is substantially pure and is free of other substances with which it is ordinarily found in nature or in in vivo systems to an extent practical and appropriate for its intended use. In particular, the immunostimulatory ODN are sufficiently pure and are sufficiently free from other biological constituents of cells so as to be useful in, for example, producing pharmaceutical preparations. Because an isolated immunostimulatory ODN of the invention may be admixed with a pharmaceutically acceptable carrier in a pharmaceutical preparation, the immunostimulatory ODN may comprise only a small percentage by weight of the preparation. The immunostimulatory ODN is nonetheless substantially pure in that it has been substantially separated from the substances with which it may be associated in living systems.

The immunostimulatory nucleic acid molecules may have a chimeric backbone. For purposes of the instant invention, a chimeric backbone refers to a partially stabilized backbone, wherein at least one internucleotide linkage is phosphodiester or phosphodiester-like, and wherein at least one other internucleotide linkage is a stabilized internucleotide linkage, wherein the at least one phosphodiester or phosphodiester-like linkage and the at least one stabilized linkage are different. Since boranophosphonate linkages have been reported to be stabilized relative to phosphodiester linkages, for purposes of the chimeric nature of the backbone, boranophosphonate linkages can be classified either as phosphodiester-like or as stabilized, depending on the context. For example, a chimaeric backbone according to the instant invention could in one embodiment include at least one phosphodiester (phosphodiester or phosphodiester-like) linkage and at least one boranophosphonate (stabilized) linkage. In another embodiment a chimeric backbone according to the instant invention could include boranophosphonate (phosphodiester or phosphodiester-like) and phosphorothioate (stabilized) linkages. A “stabilized internucleotide linkage” shall mean an internucleotide linkage that is relatively resistant to in vivo degradation (e.g., via an exo- or endo-nuclease), compared to a phosphodiester internucleotide linkage. Preferred stabilized internucleotide linkages include, without limitation, phosphorothioate, phosphorodithioate, methylphosphonate, and methylphosphorothioate. Other stabilized internucleotide linkages include, without limitation: peptide, alkyl, dephospho, and others as described above.

Modified backbones such as phosphorothioates may be synthesized using automated techniques employing either phosphoramidate or H-phosphonate chemistries. Aryl- and alkyl-phosphonates can be made, e.g., as described in U.S. Pat. No. 4,469,863; and alkylphosphotriesters (in which the charged oxygen moiety is alkylated as described in U.S. Pat. No. 5,023,243 and European Patent No. 092,574) can be prepared by automated solid phase synthesis using commercially available reagents. Methods for making other DNA backbone modifications and substitutions have been described. Uhlmann E et al (1990) Chem Rev 90:544; Goodchild J (1990) Bioconjugate Chem 1:165. Methods for preparing chimeric oligonucleotides are also known. For instance patents issued to Uhlmann et al have described such techniques.

Mixed backbone modified ODN may be synthesized using a commercially available DNA synthesizer and standard phosphoramidite chemistry. (P. B. Eckstein, “Oligonucleotides and Analogs—A Practical Approach” IRL Press, Oxford, UK, 1991, and M. D. Matteucci and M. H. Caruthers, Tetrahedron Lett. 21, 719 (1980)) After coupling, PS linkages are introduced by sulfurization using the Beaucage reagent (R. P. Iyer, W. Egan. J. B. Regan and S. L. Beaucage, J. Am. Chem. Soc. 112, 1253 (1990)) (0.075 M in acetonitrile) or phenyl acetyl disulfide (PADS) followed by capping with acetic anhydride, 2,6-lutidine in tetrahydrofurane (1:1:8; v:v:v) and N-methylimidazole (16% in tetrahydrofurane). This capping step is performed after the sulfurization reaction to minimize formation of undesired phosphodiester (PO) linkages at positions where a phosphorothioate linkage should be located. In the case of the introduction of a phosphodiester linkage, e.g. at a CpG dinucleotide, the intermediate phosphorous-III is oxidized by treatment with a solution of iodine in water/pyridine. After cleavage from the solid support and final deprotection by treatment with concentrated ammonia (15 hrs at 50° C.), the ODN are analyzed by HPLC on a Gen-Pak Fax column (Millipore-Waters) using a NaCl-gradient (e.g. buffer A: 10 mM NaH₂PO₄ in acetonitrile/water=1:4/v:v pH 6.8; buffer B: 10 mM NaH₂PO₄, 1.5 M NaCl in acetonitrile/water=1:4/v:v; 5 to 60% B in 30 minutes at 1 ml/min) or by capillary gel electrophoresis. The ODN can be purified by HPLC or by FPLC on a Source High Performance column (Amersham Pharmacia). HPLC-homogeneous fractions are combined and desalted via a C18 column or by ultrafiltration. The ODN was analyzed by MALDI-TOF mass spectrometry to confirm the calculated mass.

The nucleic acids of the invention can also include other modifications. These include nonionic DNA analogs, such as alkyl- and aryl-phosphates (in which the charged phosphonate oxygen is replaced by an alkyl or aryl group), phosphodiester and alkylphosphotriesters, in which the charged oxygen moiety is alkylated. Nucleic acids which contain diol, such as tetraethyleneglycol or hexaethyleneglycol, at either or both termini have also been shown to be substantially resistant to nuclease degradation.

In some embodiments the oligonucleotides may be soft or semi-soft oligonucleotides. A soft oligonucleotide is an immunostimulatory oligonucleotide having a partially stabilized backbone, in which phosphodiester or phosphodiester-like internucleotide linkages occur only within and immediately adjacent to at least one internal pyrimidine-purine dinucleotide (YZ). Preferably YZ is YG, a pyrimidine-guanosine (YG) dinucleotide. The at least one internal YZ dinucleotide itself has a phosphodiester or phosphodiester-like internucleotide linkage. A phosphodiester or phosphodiester-like internucleotide linkage occurring immediately adjacent to the at least one internal YZ dinucleotide can be 5′, 3′, or both 5′ and 3′ to the at least one internal YZ dinucleotide.

In particular, phosphodiester or phosphodiester-like internucleotide linkages involve “internal dinucleotides”. An internal dinucleotide in general shall mean any pair of adjacent nucleotides connected by an internucleotide linkage, in which neither nucleotide in the pair of nucleotides is a terminal nucleotide, i.e., neither nucleotide in the pair of nucleotides is a nucleotide defining the 5′ or 3′ end of the oligonucleotide. Thus a linear oligonucleotide that is n nucleotides long has a total of n-1 dinucleotides and only n-3 internal dinucleotides. Each internucleotide linkage in an internal dinucleotide is an internal internucleotide linkage. Thus a linear oligonucleotide that is n nucleotides long has a total of n-1 internucleotide linkages and only n-3 internal internucleotide linkages. The strategically placed phosphodiester or phosphodiester-like internucleotide linkages, therefore, refer to phosphodiester or phosphodiester-like internucleotide linkages positioned between any pair of nucleotides in the nucleic acid sequence. In some embodiments the phosphodiester or phosphodiester-like internucleotide linkages are not positioned between either pair of nucleotides closest to the 5′ or 3′ end.

Preferably a phosphodiester or phosphodiester-like internucleotide linkage occurring immediately adjacent to the at least one internal YZ dinucleotide is itself an internal internucleotide linkage. Thus for a sequence N₁YZ N₂, wherein N₁ and N₂ are each, independent of the other, any single nucleotide, the YZ dinucleotide has a phosphodiester or phosphodiester-like internucleotide linkage, and in addition (a) N₁ and Y are linked by a phosphodiester or phosphodiester-like internucleotide linkage when N₁ is an internal nucleotide, (b) Z and N₂ are linked by a phosphodiester or phosphodiester-like internucleotide linkage when N₂ is an internal nucleotide, or (c) N₁ and Y are linked by a phosphodiester or phosphodiester-like internucleotide linkage when N₁ is an internal nucleotide and Z and N₂ are linked by a phosphodiester or phosphodiester-like internucleotide linkage when N₂ is an internal nucleotide.

In the oligonucleotide of the invention at least one YZ of R₁YZR₂ may have a phosphodiester linkage. Alternatively the YZ of R₁YZR₂ may have a phosphorothioate linkage. In some embodiments the R₁Y and or ZR₂ of R₁YZR₂ have a phosphorothioate linkage.

Soft oligonucleotides according to the instant invention are believed to be relatively susceptible to nuclease cleavage compared to completely stabilized oligonucleotides. Without meaning to be bound to a particular theory or mechanism, it is believed that soft oligonucleotides of the invention are cleavable to fragments with reduced or no immunostimulatory activity relative to fall-length soft oligonucleotide. Incorporation of at least one nuclease-sensitive internucleotide linkage, particularly near the middle of the oligonucleotide, is believed to provide an “off switch” which alters the pharmacokinetics of the oligonucleotide so as to reduce the duration of maximal immunostimulatory activity of the oligonucleotide. This can be of particular value in tissues and in clinical applications in which it is desirable to avoid injury related to chronic local inflammation or immunostimulation, e.g., the kidney.

A semi-soft oligonucleotide is an immunostimulatory oligonucleotide having a partially stabilized backbone, in which phosphodiester or phosphodiester-like internucleotide linkages occur only within at least one internal pyrimidine-purine (YZ) dinucleotide. Semi-soft oligonucleotides generally possess increased immunostimulatory potency relative to corresponding fully stabilized immunostimulatory oligonucleotides. Due to the greater potency of semi-soft oligonucleotides, semi-soft oligonucleotides may be used, in some instances, at lower effective concentations and have lower effective doses than conventional fully stabilized immunostimulatory oligonucleotides in order to achieve a desired biological effect.

It is believed that the foregoing properties of semi-soft oligonucleotides generally increase with increasing “dose” of phosphodiester or phosphodiester-like internucleotide linkages involving internal YZ dinucleotides. Thus it is believed, for example, that generally for a given oligonucleotide sequence with five internal YZ dinucleotides, an oligonucleotide with five internal phosphodiester or phosphodiester-like YZ internucleotide linkages is more immunostimulatory than an oligonucleotide with four internal phosphodiester or phosphodiester-like YG internucleotide linkages, which in turn is more immunostimulatory than an oligonucleotide with three internal phosphodiester or phosphodiester-like YZ internucleotide linkages, which in turn is more immunostimulatory than an oligonucleotide with two internal phosphodiester or phosphodiester-like YZ internucleotide linkages, which in turn is more immunostimulatory than an oligonucleotide with one internal phosphodiester or phosphodiester-like YZ internucleotide linkage. Importantly, inclusion of even one internal phosphodiester or phosphodiester-like YZ internucleotide linkage is believed to be advantageous over no internal phosphodiester or phosphodiester-like YZ internucleotide linkage. In addition to the number of phosphodiester or phosphodiester-like internucleotide linkages, the position along the length of the nucleic acid can also affect potency.

The soft and semi-soft oligonucleotides will generally include, in addition to the phosphodiester or phosphodiester-like internucleotide linkages at preferred internal positions, 5′ and 3′ ends that are resistant to degradation. Such degradation-resistant ends can involve any suitable modification that results in an increased resistance against exonuclease digestion over corresponding unmodified ends. For instance, the 5′ and 3′ ends can be stabilized by the inclusion there of at least one phosphate modification of the backbone. In a preferred embodiment, the at least one phosphate modification of the backbone at each end is independently a phosphorothioate, phosphorodithioate, methylphosphonate, or methylphosphorothioate internucleotide linkage. In another embodiment, the degradation-resistant end includes one or more nucleotide units connected by peptide or amide linkages at the 3′ end.

A phosphodiester internucleotide linkage is the type of linkage characteristic of nucleic acids found in nature. The phosphodiester internucleotide linkage includes a phosphorus atom flanked by two bridging oxygen atoms and bound also by two additional oxygen atoms, one charged and the other uncharged. Phosphodiester internucleotide linkage is particularly preferred when it is important to reduce the tissue half-life of the oligonucleotide.

A phosphodiester-like internucleotide linkage is a phosphorus-containing bridging group that is chemically and/or diastereomerically similar to phosphodiester. Measures of similarity to phosphodiester include susceptibility to nuclease digestion and ability to activate RNAse H. Thus for example phosphodiester, but not phosphorothioate, oligonucleotides are susceptible to nuclease digestion, while both phosphodiester and phosphorothioate oligonucleotides activate RNAse H. In a preferred embodiment the phosphodiester-like internucleotide linkage is boranophosphate (or equivalently, boranophosphonate) linkage. U.S. Pat. No. 5,177,198; U.S. Pat. No. 5,859,231; U.S. Pat. No. 6,160,109; U.S. Pat. No. 6,207,819; Sagueev et al., (1998) J Am Chem Soc 120:9417-27. In another preferred embodiment the phosphodiester-like internucleotide linkage is diasteromerically pure Rp phosphorothioate. It is believed that diasteromerically pure Rp phosphorothioate is more susceptible to nuclease digestion and is better at activating RNAse H than mixed or diastereomerically pure Sp phosphorothioate. Stereoisomers of CpG oligonucleotides are the subject of co-pending U.S. patent application Ser. No. 09/361,575 filed Jul. 27, 1999, and published PCT application PCT/US99/17100 (WO 00/06588). It is to be noted that for purposes of the instant invention, the term “phosphodiester-like internucleotide linkage” specifically excludes phosphorodithioate and methylphosphonate internucleotide linkages.

As described above the soft and semi-soft oligonucleotides of the invention may have phosphodiester like linkages between C and G. One example of a phosphodiester-like linkage is a phosphorothioate linkage in an Rp conformation. Oligonucleotide p-chirality can have apparently opposite effects on the immune activity of a CpG oligonucleotide, depending upon the time point at which activity is measured. At an early time point of 40 minutes, the R_(p) but not the S_(P) stereoisomer of phosphorothioate CpG oligonucleotide induces JNK phosphorylation in mouse spleen cells. In contrast, when assayed at a late time point of 44 hr, the S_(P) but not the R_(p) stereoisomer is active in stimulating spleen cell proliferation. This difference in the kinetics and bioactivity of the R_(p) and S_(P) stereoisomers does not result from any difference in cell uptake, but rather most likely is due to two opposing biologic roles of the p-chirality. First, the enhanced activity of the Rp stereoisomer compared to the Sp for stimulating immune cells at early time points indicates that the Rp may be more effective at interacting with the CpG receptor, TLR9, or inducing the downstream signaling pathways. On the other hand, the faster degradation of the Rp PS-oligonucleotides compared to the Sp results in a much shorter duration of signaling, so that the Sp PS-oligonucleotides appear to be more biologically active when tested at later time points.

A surprisingly strong effect is achieved by the p-chirality at the CpG dinucleotide itself. In comparison to a stereo-random CpG oligonucleotide the congener in which the single CpG dinucleotide was linked in Rp was slightly more active, while the congener containing an Sp linkage was nearly inactive for inducing spleen cell proliferation.

The terms “nucleic acid” and “oligonucleotide” also encompass nucleic acids or oligonucleotides with substitutions or modifications, such as in the bases and/or sugars. For example, they include nucleic acids having backbone sugars that are covalently attached to low molecular weight organic groups other than a hydroxyl group at the 2′ position and other than a phosphate group or hydroxy group at the 5′ position. Thus modified nucleic acids may include a 2′-O-alkylated ribose group. In addition, modified nucleic acids may include sugars such as arabinose or 2′-fluoroarabinose instead of ribose. Thus the nucleic acids may be heterogeneous in backbone composition thereby containing any possible combination of polymer units linked together such as peptide-nucleic acids (which have an amino acid backbone with nucleic acid bases).

Nucleic acids also include substituted purines and pyrimidines such as C-5 propyne pyrimidine and 7-deaza-7-substituted purine modified bases. Wagner R W et al. (1996) Nat Biotechnol 14:840-4. Purines and pyrimidines include but are not limited to adenine, cytosine, guanine, thymine, 5-methylcytosine, 5-hydroxycytosine, 5-fluorocytosine, 2-aminopurine, 2-amino-6-chloropurine, 2,6-diaminopurine, hypoxanthine, and other naturally and non-naturally occurring nucleobases, substituted and unsubstituted aromatic moieties. Other such modifications are well known to those of skill in the art.

The immunostimulatory oligonucleotides of the instant invention can encompass various chemical modifications and substitutions, in comparison to natural RNA and DNA, involving a phosphodiester internucleotide bridge, a β-D-ribose unit and/or a natural nucleotide base (adenine, guanine, cytosine, thymine, uracil). Examples of chemical modifications are known to the skilled person and are described, for example, in Uhlmann B et al. (1990) Chem Rev 90:543; “Protocols for Oligonucleotides and Analogs” Synthesis and Properties & Synthesis and Analytical Techniques, S. Agrawal, Ed, Humana Press, Totowa, USA 1993; Crooke S T et al. (1996) Annu Rev Pharmacol Toxicol 36:107-129; and Hunziker J et al. (1995) Mod Synth Methods 7:331-417. An oligonucleotide according to the invention may have one or more modifications, wherein each modification is located at a particular phosphodiester internucleotide bridge and/or at a particular β-D-ribose unit and/or at a particular natural nucleotide base position in comparison to an oligonucleotide of the same sequence which is composed of natural DNA or RNA.

For example, the invention relates to an oligonucleotide which may comprise one or more modifications and wherein each modification is independently selected from:

-   a) the replacement of a phosphodiester internucleotide bridge     located at the 3′ and/or the 5′ end of a nucleotide by a modified     internucleotide bridge, -   b) the replacement of phosphodiester bridge located at the 3′ and/or     the 5′ end of a nucleotide by a dephospho bridge, -   c) the replacement of a sugar phosphate unit from the sugar     phosphate backbone by another unit, -   d) the replacement of a β-D-ribose unit by a modified sugar unit,     and -   e) the replacement of a natural nucleotide base by a modified     nucleotide base.

More detailed examples for the chemical modification of an olignucleotide are as follows.

A phosphodiester internucleotide bridge located at the 3′ and/or the 5′ end of a nucleotide can be replaced by a modified internucleotide bridge, wherein the modified internucleotide bridge is for example selected from phosphorothioate, phosphorodithioate, NR¹R²-phosphoramidate, boranophosphate, α-hydroxybenzyl phosphonate, phosphate-(C₁-C₂₁)—O-alkyl ester, phosphate-[(C₆-C₁₂)aryl-(C₁-C₂₁)—O-alkyl]ester, (C₁-C₈)alkylphosphonate and/or (C₆-C₁₂)arylphosphonate bridges, (C₇-C₁₂)-α-hydroxymethyl-aryl (e.g., disclosed in WO 95/01363), wherein (C₆-C₁₂)aryl, (C₆-C₂₀)aryl and (C₆-C₁₄)aryl are optionally substituted by halogen, alkyl, alkoxy, nitro, cyano, and where R¹ and R² are, independently of each other, hydrogen, (C₁-C₁₈)-alkyl, (C₆-C₂₀)-aryl, (C₆-C₁₄)-aryl-(C₁-C₈)-alkyl, preferably hydrogen, (C₁-C₈)-alkyl, preferably (C₁-C₄)-alkyl and/or methoxyethyl, or R¹ and R² form, together with the nitrogen atom carrying then, a 5-6-membered heterocyclic ring which can additionally contain a further heteroatom from the group O, S and N.

The replacement of a phosphodiester bridge located at the 3′ and/or the 5′ end of a nucleotide by a dephospho bridge (dephospho bridges are described, for example, in Uhlmanm E and Peyman A in “Methods in Molecular Biology”, Vol. 20, “Protocols for Oligonucleotides and Analogs”, S. Agrawal, Ed., Humana Press, Totowa 1993, Chapter 16, pp. 355 ft), wherein a dephospho bridge is for example selected from the dephospho bridges formacetal, 3′-thioformacetal, methylhydroxylamine, oxime, methylenedimethyl-hydrazo, dimethylenesulfone and/or silyl groups.

A sugar phosphate unit (i.e., a β-D-ribose and phosphodiester internucleotide bridge together forming a sugar phosphate unit) from the sugar phosphate backbone (i.e., a sugar phosphate backbone is composed of sugar phosphate units) can be replaced by another unit, wherein the other unit is for example suitable to build up a “morpholino-derivative” oligomer (as described, for example, in Stirchak E P et al. (1989) Nucleic Acids Res 17:6129-41), that is, e.g., the replacement by a morpholino-derivative unit; or to build up a polyamide nucleic acid (“PNA”; as described for example, in Nielsen P E et al. (1994) Bioconjug Chem 5:3-7), that is, e.g., the replacement by a PNA backbone unit, e.g., by 2-aminoethylglycine.

A β-ribose unit or a β-D-2′-deoxyribose unit can be replaced by a modified sugar unit, wherein the modified sugar unit is for example selected from β-D-ribose, α-D-2′-deoxyribose, L-2′-deoxyribose, 2′-F-2′-deoxyribose, 2′-F-arabinose, 2′-O—(C₁-C₆)alkyl-ribose, preferably 2′-O—(C₁-C₆)alkyl-ribose is 2′-O-methylribose, 2′-O—(C₂-C₆)alkenyl-ribose, 2′-[O—(C₁-C₆)alkyl-O—(C₁-C₆)alkyl]-ribose, 2′-NH₂-2′-deoxyribose, β-D-xylo-furanose, α-arabinofuranose, 2,4-dideoxy-β-D-erythro-hexo-pyranose, and carbocyclic (described, for example, in Froehler J (1992) Am Chem Soc 114:8320) and/or open-chain sugar analogs (described, for example, in Vandendriessche et al. (1993) Tetrahedron 49:7223) and/or bicyclosugar analogs (described, for example, in Tarkov M et al. (1993) Helv Chim Acta 76:481).

In some preferred embodiments the sugar is 2′-O-methylribose, particularly for one or both nucleotides linked by a phosphodiester or phosphodiester-like internucleotide linkage.

Nucleic acids also include substituted purines and pyrimidines such as C-5 propyne pyrimidine and 7-deaza-7-substituted purine modified bases. Wagner R W et al. (1996) Nat Biotechnol 14:840-4. Purines and pyrimidines include but are not limited to adenine, cytosine, guanine, and thymine, and other naturally and non-naturally occurring nucleobases, substituted and unsubstituted aromatic moieties.

A modified base is any base which is chemically distinct from the naturally occurring bases typically found in DNA and RNA such as T, C, G, A, and U, but which share basic chemical structures with these naturally occurring bases. The modified nucleotide base may be, for example, selected from hypoxanthine, uracil, dihydrouracil, pseudouracil, 2-thiouracil, 4-thiouracil, 5-aminouracil, 5-(C₁-C₆)-alkyluracil, 5-(C₂-C₆)-alkenyluracil, 5-(C₂-C₆)-alkynyluracil, 5-(hydroxymethyl)uracil, 5-chlorouracil, 5-fluorouracil, 5-bromouracil, 5-hydroxycytosine, 5-(C₁-C₆)-alkylcytosine, 5-(C₂-C₆)-alkenylcytosine, 5-(C₂-C₆)-alkynylcytosine, 5-chlorocytosine, 5-fluorocytosine, 5-bromocytosine, N²-dimethylguanine, 2,4-diamino-purine, 8-azapurine, a substituted 7-deazapurine, preferably 7-deaza-7-substituted and/or 7-deaza-8-substituted purine, 5-hydroxymethylcytosine, N4-alkylcytosine, e.g., N4-ethylcytosine, 5-hydroxydeoxycytidine, 5-hydroxymethyldeoxycytidine, N4-alkyldeoxycytidine, e.g., N4-ethyldeoxycytidine, 6-thiodeoxyguanosine, and deoxyribonucleotides of nitropyrrole, C5-propynylpyrimidine, and diaminopurine e.g., 2,6-diaminopurine, inosine, 5-methylcytosine, 2-aminopurine, 2-amino-6-chloropurine, hypoxanthine or other modifications of a natural nucleotide bases. This list is meant to be exemplary and is not to be interpreted to be limiting.

In particular formulas described herein a set of modified bases is defined. For instance the letter Y is used to refer to pyrimidine and in some embodiments a nucleotide containing a cytosine or a modified cytosine. A modified cytosine as used herein is a naturally occurring or non-naturally occurring pyrimidine base analog of cytosine which can replace this base without impairing the immunostimulatory activity of the oligonucleotide. Modified cytosines include but are not limited to 5-substituted cytosines (e.g. 5-methyl-cytosine, 5-fluoro-cytosine, 5-chloro-cytosine, 5-bromocytosine 5-iodo-cytosine, 5-hydroxy-cytosine, 5-hydroxymethyl-cytosine, 5-difluoromethyl-cytosine, and unsubstituted or substituted 5-alkynyl-cytosine), 6-substituted cytosines, N4-substituted cytosines (e.g. N4-ethyl-cytosine), 5-aza-cytosine, 2-mercapto-cytosine, isocytosine, pseudo-isocytosine, cytosine analogs with condensed ring systems (e.g. N,N′-propylene cytosine or phenoxazine), and uracil and its derivatives (e.g. 5-fluoro-uracil, 5-bromo-uracil, 5-bromovinyl-uracil, 4-thio-uracil, 5-hydroxy-uracil, 5-propynyl-uracil). Some of the preferred cytosines include 5-methyl-cytosine, 5-fluoro-cytosine, 5-hydroxy-cytosine, 5-hydroxymethyl-cytosine, and N4-ethyl-cytosine. In another embodiment of the invention, the cytosine base is substituted by a universal base (e.g. 3-nitropyrrole, P-base), an aromatic ring system (e.g. fluorobenzene or difluorobenzene) or a hydrogen atom (dSpacer).

The letter Z is used to refer to a purine, pyrimidine, or abasic and in some embodiments a guanine or a modified guanine base. A modified guanine as used herein is a naturally occurring or non-naturally occurring purine base analog of guanine which can replace this base without impairing the immunostimulatory activity of the oligonucleotide. Modified guanines include but are not limited to 7-deazaguanine, 7-deaza-7-substituted guanine (such as 7-deaza-7-(C2-C6)alkynylguanine), 7-deaza-8-substituted guanine, hypoxanthine, N2-substituted guanines (e.g. N2-methyl-guanine), 5-amino-3-methyl-3H,6H-thiazolo[4,5-d]pyrimidine-2,7-dione, 2,6-diaminopurine, 2-aminopurine, purine, indole, adenine, substituted adenines (e.g. N6-methyl-adenine, 8-oxo-adenine) 8-substituted guanine (e.g. 8-hydroxyguanine and 8-bromoguanine) and 6-thioguanine. In another embodiment of the invention, the guanine base is substituted by a universal base (e.g. 4-methyl-indole, 5-nitro-indole, and K-base), an aromatic ring system (e.g. benzimidazole or dichloro-benzimidazole, 1-methyl-1H-[1,2,4]triazolo-3-carboxylic acid amide) or a hydrogen atom (dSpacer).

The oligonucleotides may have one or more accessible 5′ ends. It is possible to create modified oligonucleotides having two such 5′ ends. This may be achieved, for instance by attaching two oligonucleotides through a 3′-3′ linkage to generate an oligonucleotide having one or two accessible 5′ ends. The 33′-linkage may be a phosphodiester, phosphorothioate or any other modified internucleotide bridge. Methods for accomplishing such linkages are known in the art. For instance, such linkages have been described in Seliger, H.; et al., Oligonucleotide analogs with terminal 3′-3′- and 5′-5′-internucleotidic linkages a antisense inhibitors of viral gene expression, Nucleotides & Nucleotides (1991), 10(1-3), 469-77 and Jiang, et al., Pseudo-cyclic oligonucleotides: in vitro and in vivo properties, Bioorganic & Medicinal Chemistry (1999), 7(12), 2727-2735.

Additionally, 3′3′-linked nucleic acids where the linkage between the 3′-terminal nucleotides is not a phosphodiester, phosphorothioate or other modified bridge, can be prepared using an additional spacer, such as tri- or tetra-ethylenglycol phosphate moiety (Durand, M. et al, Triple-helix formation by an oligonucleotide containing one (dA)12 and two (dT)12 sequences bridged by two hexaethylene glycol chains, Biochemistry (1992), 31(38), 9197-204, U.S. Pat. No. 5,658,738, and U.S. Pat. No. 5,668,265). Alternatively, the non-nucleotidic linker may be derived from ethanediol, propanediol, or from an abasic deoxyribose (dSpacer) unit (Fontanel, Marie Laurence et al., Sterical recognition by T4 polynucleotide kinase of non-nucleosidic moieties 5′-attached to oligonucleotides; Nucleic Acids Research (1994), 22(11), 2022-7) using standard phosphoramidite chemistry. The non-nucleotidic linkers can be incorporated once or multiple times, or combined with each other allowing for any desirable distance between the 3′-ends of the two ODNs to be linked.

The oligonucleotides are partially resistant to degradation (e.g., are stabilized). A “stabilized oligonucleotide molecule” shall mean an oligonucleotide that is relatively resistant to in vive degradation (e.g. via an exo- or endo-nuclease). Nucleic acid stabilization can be accomplished via backbone modifications. Oligonucleotides having phosphorothioate linkages provide maximal activity and protect the oligonucleotide from degradation by intracellular exo- and endo-nucleases. Other modified oligonucleotides include phosphodiester modified nucleic acids, combinations of phosphodiester and phosphorothioate nucleic acid, methylphosphonate, methylphosphorothioate, phosphorodithioate, p-ethoxy, and combinations thereof:

Modified backbones such as phosphorothioates may be synthesized using automated techniques employing either phosphoramidate or H-phosphonate chemistries. Aryl- and alkyl-phosphonates can be made, e.g., as described in U.S. Pat. No. 4,469,863; and alkylphosphotriesters (in which the charged oxygen moiety is alkylated as described in U.S. Pat. No. 5,023,243 and European Patent No. 092,574) can be prepared by automated solid phase synthesis using commercially available reagents. Methods for making other DNA backbone modifications and substitutions have been described (e.g., Uhlmann, B. and Peyman, A., Chem. Rev. 90:544, 1990; Goodchild, J., Bioconjugate Chem. 1:165, 1990).

Other stabilized oligonucleotides include: nonionic DNA analogs, such as alkyl- and aryl-phosphates (in which the charged phosphonate oxygen is replaced by an alkyl or aryl group), phosphodiester and alkylphosphotriesters, in which the charged oxygen moiety is alkylated. Nucleic acids which contain diol, such as tetraethyleneglycol or hexaethyleneglycol, at either or both termini have also been shown to be substantially resistant to nuclease degradation.

In some embodiments the oligonucleotide comprises one or more palindromic sequences. As used herein, “palindrome” and, equivalently, “palindromic sequence” shall refer to an inverted repeat, i.e., a sequence such as ABCDEE′D′C′B′A′ in which A and A′, B and B′, etc., are bases capable of forming the usual Watson-Crick base pairs. In some cases the palindrome is GC-rich. A GC-rich palindrome is a palindrome having a base composition of at least two-thirds G's and C's. In some embodiments the GC-rich domain is preferably 3′ to the “B cell stimulatory domain”. In the case of a 10-base long GC-rich palindrome, the palindrome thus contains at least 8 G's and C's. In the case of a 12-base long GC-rich palindrome, the palindrome also contains at least 8 G's and C's. In the case of a 14-mar GC-rich palindrome, at least ten bases of the palindrome are G's and C's. In some embodiments the GC-rich palindrome is made up exclusively of G's and C's. In some embodiments the oligonucleotide contains more than one palindromic sequence.

DNA is a polymer of deoxyribonucleotides joined through 3′-5′ phosphodiester linkages. Units of the polymer of the invention can also be joined through 3′-5′ phosphodiester linkages. However, the invention also encompasses polymers having unusual internucleotide linkages, including specifically 5′-5′, 3′-3′, 2′-2′, 2′-3′, and 2′-5′ internucleotide linkages. In one embodiment such unusual linkages are excluded from the immunostimulatory DNA motif, even though one or more of such linkages may occur elsewhere within the polymer. For polymers having free ends, inclusion of one 3′-3′ internucleotide linkage can result in a polymer having two free 5′ ends. Conversely, for polymers having free ends, inclusion of one 5′-5′ internucleotide linkage can result in a polymer having two free 3′ ends.

An immunostimulatory composition of this invention can contain two or more immunostimulatory DNA motifs which can be linked through a branching unit. The internucleotide linkages can be 3′-5′, 5′-5′, 3′-3′, 2′-2′, 2′-3′, or 2′-5′ linkages. Thereby, the nomenclature 2′-5′ is chosen according to the carbon atom of deoxyribose. However, if unnatural sugar moieties are employed, such as ring-expanded sugar analogs (e.g., hexanose, cylohexene or pyranose) or bi- or tricyclic sugar analogs, then this nomenclature changes according to the nomenclature of the monomer. The unusual internucleotide linkage can be a phosphodiester linkage, but it can alternatively be modified as phosphorothioate or any other modified linkage as described herein. Formula IV shows a general structure for branched DNA oligomers and modified oligoribonucleotide analogs of the invention via a nucleotidic branching unit. Thereby Nu₁, Nu₂, and Nu₃ can be linked through 3′-5′, 5′-5′, 3′-3′, 2-2′, 2′-3′, or 2′-5′-linkages. Branching of DNA oligomers can also involve the use of non-nucleotidic linkers and abasic spacers. In one embodiment, Nu₁, Nu₂, and Nu₃ represent identical or different immunostimulatory DNA motifs.

The modified oligoribonucleotide analog may contain a doubler or trebler unit (Glen Research. Sterling, Va.), in particular those modified oligodeoxyribonucleotide analogs with a 3′-3′ linkage. A doubler unit in one embodiment can be based on 1,3-bis-[5-(4,4′-dimethoxytrityloxy)pentylamido]propyl-2-[(2-cyanoethyl)-(N,N-diisopropyl)]-phosphoramidite. A trebler unit in one embodiment can be based on incorporation of Tris-2,2,2-[3-(4,4′-dimethoxytrityloxy)propyloxymethyl]ethyl-[(2-cyanoethyl)-(N,N-diisopropyl)]-phosphoramidite. Branching of the modified oligoribonucleotide analogs by multiple doubler, trebler, or other multiplier units leads to dendrimers which are a farther embodiment of this invention. Branched modified oligoribonucleotide analogs may lead to crosslinking of receptors particularly for combinations of immunostimulatory RNA and DNA such as TLR3, TLR7, TLR8, and TLR9 with distinct immune effects compared to non-branched forms of the analogs. In addition, the synthesis of branched or otherwise multimeric analogs may stabilize DNA against degradation and may enable weak or partially effective DNA sequences to exert a therapeutically useful level of immune activity. The modified oligodeoxyribonucleotide analogs may also contain linker units resulting from peptide modifying reagents or oligonucleotide modifying reagents (Glen Research). Furthermore, the modified oligodeoxyribonucleotide analogs may contain one or more natural or unnatural amino acid residues which are connected to the polymer by peptide (amide) linkages.

The 3′-5′, 5′-5′, 3′-3′, 2′-2′, 2′-3′, and 2′-5′ internucleotide linkages can be direct or indirect. Direct linkages in this context refers to a phosphate or modified phosphate linkage as disclosed herein, without an intervening linker moiety. An intervening linker moiety is an organic moiety distinct from a phosphate or modified phosphate linkage as disclosed herein, which can include, for example, polyethylene glycol, triethylene glycol, hexaethylene glycol, dSpacer (i.e., an abasic deoxynucleotide), doubler unit, or trebler unit.

The linkages are preferably composed of C, H, N, O, S, B, P, and Halogen, containing 3 to 300 atoms. An example with 3 atoms is an acetal linkage (ODN1-3′-O—CH₂—O-3′-ODN2) connecting e.g. the 3′-hydroxy group of one nucleotide to the 3′-hydroxy group of a second oligonucleotide. An example with about 300 atoms is PEG-40 (tetraconta polyethyleneglycol). Preferred linkages are phosphodiester, phosphorothioate, methylphosphonate, phosphoramidate, boranophosphonate, amide, ether, thioether, acetal, thioacetal, urea, thiourea, sulfonamide, Schiff Base and disulfide linkages. It is also possible to use the Solulink BioConjugation System i.e., (www.trilinkbiotech.com).

If the oligonucleotide is composed of two or more sequence parts, these parts can be identical or different. Thus, in an oligonucleotide with a 3′3′-linkage, the sequences can be identical 5′-ODN1-3′3′-ODN1-5′ or different 5′-ODN1-3′3′-ODN2-5′. Furthermore, the chemical modification of the various oligonucleotide parts as well as the linker connecting them may be different. Since the uptake of short oligonucleotides appears to be less efficient than that of long oligonucleotides, linking of two or more short sequences results in improved immune stimulation. The length of the short oligonucleotides is preferably 2-20 nucleotides, more preferably 3-16 nucleotides, but most preferably 5-10 nucleotides. Preferred are linked oligonucleotides which have two or more unlinked 5′-ends.

The oligonucleotide partial sequences may also be linked by non-nucleotidic linkers. A “non-nucleotidic linker” as used herein refers to any linker element that is not a nucleotide or polymer thereof (i.e., a polynucleotide), wherein a nucleotide includes a purine or pyrimidine nucleobase and a sugar phosphate, in particular abasic linkers (dSpacers), trietyhlene glycol units or hexaethylene glycol units. Further preferred linkers are alkylamino linkers, such as C3, C6, C12 aminolinkers, and also alkylthiol linkers, such as C3 or C6 thiol linkers. The oligonucleotides can also be linked by aromatic residues which may be further substituted by alkyl or substituted alkyl groups.

For facilitating uptake into cells, the immunostimulatory oligonucleotides are in some embodiments in the range of 3 to 100 bases in length. In some embodiments the oligonucleotides are 7-100 bases in length. Typically, nucleic acids of any size greater than 6 nucleotides (even many kb long) are capable of inducing an immune response according to the invention if sufficient immunostimulatory motifs are present. However, the improved immunostimulatory capacity of the modified oligonucleotides of the invention provides for immunostimulatory molecules of much shorter length. In some embodiments the immunostimulatory oligonucleotides are 3-6 bases in length.

The CpG immunostimulatory oligonucleotides are useful in some aspects of the invention as a vaccine for the treatment of a subject at risk of developing allergy or asthma, an infection with an infectious organism or a cancer in which a specific cancer antigen has been identified. The CpG immunostimulatory oligonucleotides can also be given without the antigen or allergen for protection against infection, allergy or cancer, and in this case repeated doses may allow longer team protection. A subject at risk as used herein is a subject who has any risk of exposure to an infection causing pathogen or a cancer or an allergen or a risk of developing cancer. For instance, a subject at risk may be a subject who is planning to travel to w area where a particular type of infectious agent is found or it may be a subject who through lifestyle or medical procedures is exposed to bodily fluids which may contain infectious organisms or directly to the organism or even any subject living in an area where an infectious organism or an allergen has been identified. Subjects at risk of developing infection also include general populations to which a medical agency recommends vaccination with a particular infectious organism antigen. If the antigen is an allergen and the subject develops allergic responses to that particular antigen and the subject may be exposed to the antigen, i.e., during pollen season, then that subject is at risk of exposure to the antigen. A subject at risk of developing allergy or asthma includes those subjects that have been identified as having an allergy or asthma but that don't have the active disease during the CpG immunostimulatory oligonucleotide treatment as well as subjects that are considered to be at risk of developing these diseases because of genetic or environmental factors.

A subject at risk of developing a cancer is one who has a high probability of developing cancer. These subjects include, for instance, subjects having a genetic abnormality, the presence of which has been demonstrated to have a correlative relation to a higher likelihood of developing a cancer and subjects exposed to cancer causing agents such as tobacco, asbestos, or other chemical toxins, or a subject who has previously been treated for cancer and is in apparent remission. When a subject at risk of developing a cancer is treated with an antigen specific for the type of cancer to which the subject is at risk of developing and a CpG immunostimulatory oligonucleotide, the subject may be able to kill the cancer cells as they develop. If a tumor begins to form in the subject, the subject will develop a specific immune response against the tumor antigen.

In addition to the use of the CpG immunostimulatory oligonucleotides for prophylactic treatment, the invention also encompasses the use of the CpG immunostimulatory oligonucleotides for the treatment of a subject having an infection, an allergy, asthma, or a cancer.

A subject having an infection is a subject that has been exposed to an infectious pathogen and has acute or chronic detectable levels of the pathogen in the body. The CpG immunostimulatory oligonucleotides can be used with or without an antigen to mount an antigen specific systemic or mucosal immune response that is capable of reducing the level of or eradicating the infectious pathogen. An infectious disease, as used herein, is a disease arising from the presence of a foreign microorganism in the body. It is particularly important to develop effective vaccine strategies and treatments to protect the body's mucosal surfaces, which are the primary site of pathogenic entry.

A subject having an allergy is a subject that has or is at risk of developing an allergic reaction in response to an allergen. An allergy refers to acquired hypersensitivity to a substance (allergen). Allergic conditions include but are not limited to eczema, allergic rhinitis or coryza, bay fever, conjunctivitis, bronchial asthma, urticaria (hives) and food allergies, and other atopic conditions.

Allergies are generally caused by IgE antibody generation against harmless allergens. The cytokines that are induced by systemic or mucosal administration of CpG immunostimulatory oligonucleotides are predominantly of a class called Th1 (examples are IL-12, IP-10, IFN-α and IFN-γ) and these induce both humoral and cellular immune responses. The other major type of immune response, which is associated with the production of IL-4 and IL-5 cytokines, is termed a Th2 immune response. In general, it appears that allergic diseases are mediated by Th2 type immune responses. Based on the ability of the CpG immunostimulatory oligonucleotides to shift the immune response in a subject from a predominant Th2 (which is associated with production of IgE antibodies and allergy) to a balanced Th2/Th1 response (which is protective against allergic reactions), an effective dose for inducing an immune response of a CpG immunostimulatory oligonucleotide can be administered to a subject to treat or prevent asthma and allergy.

Thus, the CpG immunostimulatory oligonucleotides have significant therapeutic utility in the treatment of allergic and non-allergic conditions such as asthma. Th2 cytokines, especially IL-4 and IL-5 are elevated in the airways of asthmatic subjects. These cytokines promote important aspects of the asthmatic inflammatory response, including IgE isotope switching, eosinophil chemotaxis and activation and mast cell growth. Th1 cytokines, especially IFN-γ and IL-12, can suppress the formation of Th2 clones and production of Th2 cytokines. Asthma refers to a disorder of the respiratory system characterized by inflammation, narrowing of the airways and increased reactivity of the airways to inhaled agents. Asthma is frequently, although not exclusively associated with atopic or allergic symptoms.

A subject having a cancer is a subject that has detectable cancerous cells. The cancer may be a malignant or non-malignant cancer. Cancers or tumors include but are not limited to biliary tract cancer, brain cancer; breast cancer, cervical cancer, choriocarcinoma; colon cancer; endometrial cancer; esophageal cancer; gastric cancer; intraepithelial neoplasms; lymphomas; liver cancer, lung cancer (e.g. small cell and non-small cell); melanoma; neuroblastomas; oral cancer, ovarian cancer; pancreas cancer; prostate cancer rectal cancer sarcomas; skin cancer; testicular cancer, thyroid cancer; and renal cancer, as well as other carcinomas and sarcomas. In one embodiment the cancer is hairy cell leukemia, chronic myelogenous leukemia, cutaneous T-cell leukemia, multiple myeloma, follicular lymphoma, malignant melanoma, squamous cell carcinoma, renal cell carcinoma, prostate carcinoma, bladder cell carcinoma, or colon carcinoma.

A subject shall mean a human or vertebrate animal including but not limited to a dog, cat, horse, cow, pig, sheep, goat, turkey, chicken, primate, e.g., monkey, and fish (aquaculture species), e.g. salmon. Thus, the invention can also be used to treat cancer and tumors, infections, and allergy/asthma in non human subjects. Cancer is one of the leading causes of death in companion animals (i.e., cats and dogs).

As used herein, the term treat, treated, or treating when used with respect to an disorder such as an infectious disease, cancer, allergy, or asthma refers to a prophylactic treatment which increases the resistance of a subject to development of the disease (e.g., to infection with a pathogen) or, in other words, decreases the likelihood that the subject will develop the disease (e.g., become infected with the pathogen) as well as a treatment after the subject has developed the disease in order to fight the disease (e.g., reduce or eliminate the infection) or prevent the disease from becoming worse.

In the instances when the CpG oligonucleotide is administered with an antigen, the subject may be exposed to the antigen. As used herein, the term exposed to refers to either the active step of contacting the subject with an antigen or the passive exposure of the subject to the antigen in vivo. Methods for the active exposure of a subject to an antigen are well-known in the art. In general, an antigen is administered directly to the subject by any means such as intravenous, intramuscular, oral, transdermal, mucosal, intranasal, intratracheal, or subcutaneous administration. The antigen can be administered systemically or locally. Methods for administering the antigen and the CpG immunostimulatory oligonucleotide are described in more detail below. A subject is passively exposed to an antigen if an antigen becomes available for exposure to the immune cells in the body. A subject may be passively exposed to an antigen, for instance, by entry of a foreign pathogen into the body or by the development of a tumor cell expressing a foreign antigen on its surface.

The methods in which a subject is passively exposed to an antigen can be particularly dependent on timing of administration of the CpG immunostimulatory oligonucleotide. For instance, in a subject at risk of developing a cancer or an infectious disease or an allergic or asthmatic response, the subject may be administered the CpG immunostimulatory oligonucleotide on a regular basis when that risk is greatest, i.e., during allergy season or after exposure to a cancer causing agent. Additionally the CpG immunostimulatory oligonucleotide may be administered to travelers before they travel to foreign lands where they are at risk of exposure to infections agents. Likewise the CpG immunostimulatory oligonucleotide may be administered to soldiers or civilians at risk of exposure to biowarfare to induce a systemic or mucosal immune response to the antigen when and if the subject is exposed to it.

An antigen as used herein is a molecule capable of provoking an immune response. Antigens include but are not limited to cells, cell extracts, proteins, polypeptides, peptides, polysaccharides, polysaccharide conjugates, peptide and non-peptide mimics of polysaccharides and other molecules, small molecules, lipids, glycolipids, carbohydrates, viruses and viral extracts and multicellular organisms such a parasites and allergens. The term antigen broadly includes any type of molecule which is recognized by a host immune system as being foreign. Antigens include but are not limited to cancer antigens, microbial antigens, and allergens.

A cancer antigen as used herein is a compound, such as a peptide or protein, associated with a tumor or cancer cell surface and which is capable of provoking an immune response when expressed on the surface of an antigen presenting cell in the context of an MHC molecule. Cancer antigens can be prepared from cancer cells either by preparing crude extracts of cancer cells, for example, as described in Cohen, et al., 1994, Cancer Research, 54:1055, by partially purifying the antigens, by recombinant technology, or by de novo synthesis of known antigens. Cancer antigens include but are not limited to antigens that are recombinantly expressed, an immunogenic portion of, or a whole tumor or cancer. Such antigens can be isolated or prepared recombinantly or by any other means known in the art.

A microbial antigen as used herein is an antigen of a microorganism and includes but is not limited to virus, bacteria, parasites, and fungi. Such antigens include the intact microorganism as well as natural isolates and fragments or derivatives thereof and also synthetic compounds which are identical to or similar to natural microorganism antigens and induce an immune response specific for that microorganism. A compound is similar to a natural microorganism antigen if it induces an immune response (humoral and/or cellular) to a natural microorganism antigen. Such antigens are used routinely in the at and are well known to those of ordinary skill in the art.

Viruses as small infectious agents which generally contain a nucleic acid core and a protein coat, but are not independently living organisms. Viruses can also take the form of infectious nucleic acids lacking a protein. A virus cannot survive in the absence of a living cell within which it can replicate. Viruses enter specific living cells either by endocytosis or direct injection of DNA (phage) and multiply, causing disease. The multiplied virus can then be released and infect additional cells. Some viruses are DNA-containing viruses and others are RNA-containing viruses. DNA viruses include Pox, Herpes, Adeno, Papova, Parvo, and Hepadna. RNA viruses include Picorna, Calici, Astro, Toga, Flavi, Corona, Paramyxo, Orthomyxo, Bunya, Arena, Rhabdo, Filo, Borna, Reo, and Retro. In some aspects, the invention also intends to treat diseases in which prions are implicated in disease progression such as for example bovine spongiform encephalopathy (i.e., mad cow disease, BSE) or scrapie infection in animals, or Creutzfeldt-Jakob disease in humans.

Viruses include, but are not limited to, enteroviruses (including, but not limited to, viruses that the family picornaviridae, such as polio virus, Coxsackie virus, echo virus), rotaviruses, adenovirus, and hepatitis virus, such as hepatitis A, B, C D and E. Specific examples of viruses that have been found in humans include but are not limited to: Retroviridae (e.g., human immunodeficiency viruses, such as HIV-1 (also referred to as HTLV-III, LAV or HTLV-II/LAV, or HIV-III; and other isolates, such as HIV-LP; Picornaviridae (e.g., polio viruses, hepatitis A virus; enteroviruses, human Coxsackie viruses, rhinoviruses, echoviruses); Caldviridae (e.g., strains that cause gastroenteritis); Togaviridae (e.g., equine encephalitis viruses, rubella viruses); Flaviviridae (e.g., dengue viruses, encephalitis viruses, yellow fever viruses); Coronaviridae (e.g., coronaviruses); Rhabdoviridae (e.g., vesicular stomatitis viruses, rabies viruses); Filoviridae (e.g., ebola viruses); Paramyxoviridae (e.g., parainfluenza viruses, mumps virus, measles virus, respiratory syncytial virus); Orthomyxoviridae (e.g., influenza viruses); Bunyaviridae (e.g., Hantaan viruses, bunya viruses, phleboviruses and Nairo viruses); Arenaviridae (hemorrhagic fever viruses); Reoviridae (e.g., reoviruses, orbiviruses and rotaviruses); Birnaviridae; Hepadnaviridae (Hepatitis B virus); Parvoviridae (parvoviruses); Papovaviridae (papillomaviruses, polyoma viruses); Adenoviridae (most adenoviruses); Herpesviridae (herpes simplex virus (HSV) 1 and 2, varicella zoster virus, cytomegalovirus (CMV)); Poxviridae (variola viruses, vaccinia viruses, pox viruses); Iridoviridae (e.g., African swine fever virus); and other viruses acute laryngotracheobronchitis virus, Alphavirus, Kaposi's sarcoma-associated herpesvirus, Newcastle disease virus, Nipah virus, Norwalk virus, Papillomavirus, parainfluenza virus, avian influenza, SARs virus, West Nile virus.

The methods of the invention are particularly useful, in some embodiments, for the treatment of Human immunodeficiency virus (HIV) and hepatitis virus. HIV, a species of retrovirus also known as human T-cell lymphotropic virus III (HTLV III), is responsible for causing the deterioration resulting in the disorder known as AIDS. HIV infects and destroys T-cells, upsetting the overall balance of the immune system, resulting in a loss in the patients ability to combat other infections and predisposing the patient to opportunistic infections which frequently prove fatal.

Viral hepatitis is an inflammation of the liver which may produce swelling, tenderness, and sometimes permanent damage to the liver. If the inflammation of the liver continues at least six months or longer, it is referred to as chronic hepatitis. There are at least five different viruses known to cause viral hepatitis, include hepatitis A, B, C D and E. Hepatitis A is generally communicated through food or drinking water contaminated with human feces. Hepatitis B generally is spread through bodily fluids such as blood. For instance, it may be spread from mother to child at birth, through sexual contact, contaminated blood transfusions and needles. Hepatitis C is quite common and like Hepatitis B is often spread through blood transfusions and contaminated needles. Hepatitis D is found most often in IV drug users who are carriers of the hepatitis B virus with which it co-associates. Hepatitis B is similar to viral hepatitis A and is generally associated with poor sanitation.

Both gram negative and gram positive bacteria serve as antigens in vertebrate animals. Such gram positive bacteria include, but are not limited to, Pasteurella species, Staphylococci species, and Streptococcus species. Gram negative bacteria include, but are not limited to, Escherichia coli, Pseudomonas species, and Salmonella species. Specific examples of infectious bacteria include but are not limited to, Helicobacter pyloris, Borelia burgdorferi, Legionella pneumophilia, Mycobacteria sps (e.g. M. tuberculosis, M. avium, M. intracellulare, M. kansaii, M. gordonae), Staphylococcus aureus, Neisseria gonorrhoeae, Neisseria meningitidis, Listeria monocytogenes, Streptococcus pyogenes (Group A Streptococcus), Streptococcus agalactiae (Group B Streptococcus), Streptococcus (viridans group). Streptococcus faecalis, Streptococcus bovis, Streptococcus (anaerobic sps.), Streptococcus pneumoniae, pathogenic Campylobacter sp., Enterococus sp., Haemophilus influenza, Bacillus antracis, corynebacterium diphtheriae, corynebacterium sp., Erysipelothrix rhusiopathiae, Clostridium perfringers, Clostridium tetani, Enterobacter aerogenes, Klebsiella pneumonirae, Pasturella multocida, Bacteroides sp., Fusobacterium nucleatum, Streptobacillus moniliformis, Treponema pallidium, Treponema pertenue, Leptospira, Rickettsia and Actinomyces israelli.

Examples of fungi include Cryptococcus neoformans, Histoplasma capsulatum, Coccidioides immitis, Blastomyces dermatitidis, Chlamydia trachomatis, Candida albicans.

Other infectious organisms (i.e., protists) include Plasmodium spp. such as Plasmodium falciparum, Plasmodium malariae, Plosmodium ovale, and Plasmodium vivax and Toxoplasma gondii. Blood-borne and/or tissues parasites include Plasmodium spp., Babesia microti, Babesia divergens, Leishmania tropica, Leishmania spp., Leishmania braziliensis, Leishmania donovani, Trypanosoma gambiense and Trypanosoma rhodesiense (African sleeping sickness), Trypanosoma cruzi (Chagas' disease), and Toxoplasma gondii.

Other medically relevant microorganisms have been described extensively in the literature, e.g., see C. G. A Thomas, Medical Microbiology, Bailliere Tindall, Great Britain 1983, the entire contents of which is hereby incorporated by reference.

An allergen refers to a substance (antigen) that can induce an allergic or asthmatic response in a susceptible subject. The list of allergens is enormous and can include pollens, insect venoms, animal dander dust, fungal spores and drugs (e.g. penicillin). Examples of natural, animal and plant allergens include but are not limited to proteins specific to the following genuses: Canine (Canis familiaris); Dermatophagoides (e.g. Dermatophagoides farinae); Felis (Felis domesticus); Ambrosia (Ambrosia artemiisfolia; Lolium (e.g. Lolium perenne or Lolium multiflorum); Cryptomeria (Cryptomeria japonica); Alternaria (Alternaria alternata); Alder, Alnus (Alnus gultinoasa); Betula (Betula verrucosa); Quercus (Quercus alba); Olea (Olea europa); Artemisia (Artemisia vulgaris); Plantago (e.g. Plantago lanceolata); Parietaria (e.g. Parietaria officinalis or Parietaria judaica); Blattella (e.g. Blattella germanica); Apis (e.g. Apis multiflorum); Cupressus (e.g. Cupressus sempervirens, Cupressus arizonica and Cupressus macrocarpa); Juniperus (e.g. Juniperus sabinoides, Juniperus virginiana, Juniperus communis and Juniperus ashei); Thuya (e.g. Thuya orientalis); Chamaecyparis (e.g. Chamaecyparis obtusa); Periplaneta (e.g. Periplaneta americana); Agropyron (e.g. Agropyron repens); Secale (e.g. Secale cereale); Tritcum (e.g. Tritcum aestivum); Dactylis (e.g. Dactylis glomerata); Festuca (e.g. Festuca elatior); Poa (e.g. Poa pratensis or Poa compressa); Avena (e.g. Avena sativa); Holcus (e.g. Holcus lanatus); Anthoxanthum (e.g. Anthoxanthum odoratum); Arrhenatherum (e.g. Arrhenatherum elatius); Agrostis (e.g. Agrostis alba); Phleum (e.g. Phleum pratense); Phalaris (e.g. Phalaris arundinacea); Paspalum (e.g. Paspalum notatum); Sorghum (e.g. Sorghum halepensis); and Bromus (e.g. Bromus inermis).

The term substantially purified as used herein refers to a polypeptide which is substantially free of other proteins, lipids, carbohydrates or other materials with which it is naturally associated. One skilled in the art can purify viral or bacterial polypeptides using standard techniques for protein purification. The substantially pure polypeptide will often yield a single major band on a non-reducing polyacrylamide gel. In the case of partially glycosylated polypeptides or those that have several start codons, there may be several bands on a non-reducing polyacrylamide gel, but these will form a distinctive pattern for that polypeptide. The purity of the viral or bacterial polypeptide can also be determined by amino-terminal amino acid sequence analysis. Other types of antigens not encoded by a nucleic acid vector such as polysaccharides, small molecule, mimics etc are included within the invention.

The oligonuclotides of the invention may be administered to a subject with an anti-microbial agent. An anti-microbial agent, as used herein, refers to a naturally-occurring or synthetic compound which is capable of killing or inhibiting infectious microorganisms. The type of anti-microbial agent useful according to the invention will depend upon the type of microorganism with which the subject is infected or at risk of becoming infected. Anti-microbial agents include but are not limited to anti-bacterial agents, anti-viral agents, anti-fungal agents and anti-parasitic agents. Phrases such as “anti-infective agent”, “anti-bacterial agent”, “anti-viral agent”, “anti-fungal agent”, “anti-parasitic agent” and “parasiticide” have well-established meanings to those of ordinary skill in the art and are defined in standard medical texts. Briefly, anti-bacterial agents kill or inhibit bacteria, and include antibiotics as well as other synthetic or natural compounds having similar functions. Antibiotics are low molecular weight molecules which are produced as secondary metabolites by cells, such as microorganisms. In general, antibiotics interfere with one or more bacterial functions or structures which are specific for the microorganism and which are not present in host cells. Anti-viral agents can be isolated from natural sources or synthesized and are useful for killing or inhibiting viruses. Anti-fungal agents are used to treat superficial fungal infections as well as opportunistic and primary systemic fungal infections. Anti-parasite agents kill or inhibit parasites.

Examples of anti-parasitic agents, also referred to as parasiticides useful for human administration include but are not limited to albendazole, amphotericin B, benzidazole, bithionol, chloroquine HCl, chloroquine phosphate, clindamycin, dehydroemetine, diethylcarbamazine, diloxanide furoate, eflornithine, furazolidone, glucocorticoids, halofantrine, iodoquinol, ivermectin, mebendazole, mefloquine, meglumine antimoniate, melarsoprol, metrifonate, metronidazole, niclosamide, nifurtimox, oxamniquine, paromomycin, pentamidine isethionate, piperazine, praziquantel, primaquine phosphate, proguanil, pyrantel pamoate, pyrimethanmine-sulfonamides, pyrimethanmine-sulfadoxine, quinacrine HC, quinine sulfate, quinidine gluconate, spiramycin, stibogluconate sodium (sodium antimony gluconate), suramin, tetracycline, doxycycline, thiabendazole, tinidazole, trimethroprim-sulfamethoxazole, and tryparsamide some of which are used alone or in combination with others.

Antibacterial agents kill or inhibit the growth or function of bacteria. A large class of antibacterial agents is antibiotics. Antibiotics, which are effective for killing or inhibiting a wide range of bacteria, are referred to as broad spectrum antibiotics. Other types of antibiotics are predominantly effective against the bacteria of the class gram-positive or gram-negative. These types of antibiotics are referred to as narrow spectrum antibiotics. Other antibiotics which are effective against a single organism or disease and not against other types of bacteria, are referred to as limited spectrum antibiotics. Antibacterial agents are sometimes classified based on their primary mode of action. In general, antibacterial agents are cell wall synthesis inhibitors, cell membrane inhibitors, protein synthesis inhibitors, nucleic acid synthesis or functional inhibitors, and competitive inhibitors.

Antiviral agents are compounds which prevent infection of cells by viruses or replication of the virus within the cell. There are many fewer antiviral drugs than antibacterial drugs because the process of viral replication is so closely related to DNA replication within the host cell, that non-specific antiviral agents would often be toxic to the host. There are several stages within the process of viral infection which can be blocked or inhibited by antiviral agents. These stages include, attachment of the virus to the host cell (immunoglobulin or binding peptides), uncoating of the virus (e.g. amantadine), synthesis or translation of viral mRNA (e.g. interferon), replication of viral RNA or DNA (e.g. nucleotide analogs), maturation of new virus proteins (e.g. protease inhibitors), and budding and release of the virus.

Nucleotide analogs are synthetic compounds which are similar to nucleotides, but which have an incomplete or abnormal deoxyribose or ribose group. Once the nucleotide analogs are in the cell, they are phosphorylated, producing the triphosphate formed which competes with normal nucleotides for incorporation into the viral DNA or RNA. Once the triphosphate form of the nucleotide analog is incorporated into the growing nucleic acid chain, it causes irreversible association with the viral polymerase and thus chain termination. Nucleotide analogs include, but are not limited to, acyclovir (used for the treatment of herpes simplex virus and varicella-zoster virus), gancyclovir (useful for the treatment of cytomegalovirus), idoxuridine, ribavirin (useful for the treatment of respiratory syncitial virus), dideoxyinosine, dideoxycytidine, zidovudine (azidothymidine), imiquimod, and resimiquimod.

The interferons are cytokines which are secreted by virus-infected cells as well as immune cells. The interferons function by binding to specific receptors on cells adjacent to the infected cells, causing the change in the cell which protects it from infection by the virus. α and β-interferon also induce the expression of Class I and Class II MHC molecules on the surface of infected cells, resulting in increased antigen presentation for host immune cell recognition. α and β-interferons are available a recombinant forms and have been used for the treatment of chronic hepatitis B and C infection. At the dosages which are effective for anti-viral therapy, interferons have severe side effects such as fever, malaise and weight loss.

Anti-viral agents useful in the invention include but are not limited to immunoglobulins, amantadine, interferons, nucleotide analogs, and protease inhibitors. Specific examples of anti-virals include but are not limited to Acemannan; Acyclovir; Acyclovir Sodium; Adefovir; Alovudine; Alvircept Sudotox; Amantadine Hydrochloride; Aranotin; Arildone; Atevirdine Mesylate; Avridine; Cidofovir, Cipamnfylline; Cytarabine Hydrochloride; Delavirdine Mesylate; Desciclovir, Didanosine; Disoxaril; Edoxudine; Enviradene; Enviroxime; Famciclovir; Famotine Hydrochloride; Fiacitabine; Fialuridine; Fosarilate; Foscarnet Sodium; Fosfonet Sodium; Ganciclovir; Ganciclovir Sodium; Idoxuridine; Kethoxal; Lamivudine; Lobucavir; Memotine Hydrochloride; Methisazone; Nevirapine; Penciclovir; Pirodavir; Ribavirin; Rimantadine Hydrochloride; Saquinavir Mesylate; Somantadine Hydrochloride; Sorivudine; Statolon; Stavudine; Tilorone Hydrochloride; Trifluridine; Valacyclovir Hydrochloride; Vidarabine; Vidarabine Phosphate, Vidarabine Sodium Phosphate; Viroxime; Zalcitabine; Zidovudine; and Zinviroxime.

Anti-fungal agents are useful for the treatment and prevention of infective fungi. Anti-fungal agents are sometimes classified by their mechanism of action. Some anti-fungal agents function a cell wall inhibitors by inhibiting glucose synthase. These include, but are not limited to, basiungin/ECB. Other anti-fungal agents function by destabilizing membrane integrity. These include, but are not limited to, immidazoles, such as clotrimazole, sertaconzole, fluconazole, itraconazole, ketoconazole, miconazole, and voriconacole, as well as FK 463, amphotericin B, BAY 38-9502, MK 991, pradimicin, UK 292, butenafine, and terbinafine. Other anti-fungal agents function by breaking down chitin (e.g. chitinase) or immunosuppression (501 cream).

CpG immunostimulatory oligonucleotides can be combined with other therapeutic agents such as adjuvants to enhance immune responses. The CpG immunostimulatory oligonucleotide and other therapeutic agent may be administered simultaneously or sequentially. When the other therapeutic agents are administered simultaneously they can be administered in the same or separate formulations, but are administered at the same time. The other therapeutic agents are administered sequentially with one another and with CpG immunostimulatory oligonucleotide, when the administration of the other therapeutic agents and the CpG immunostimulatory oligonucleotide is temporally separated. The separation in time between the administration of these compounds may be a matter of minutes or it may be longer. Other therapeutic agents include but are not limited to adjuvants, cytokines, antibodies, antigens, etc.

The compositions of the invention may also be administered with non-nucleic acid adjuvants. A non-nucleic acid adjuvant is any molecule or compound except for the CpG immunostimulatory oligonucleotides described herein which can stimulate the humoral and/or cellular immune response. Non-nucleic acid adjuvants include, for instance, adjuvants that create a depo effect, immune stimulating adjuvants, and adjuvants that create a depo effect and stimulate the immune system.

The CpG immunostimulatory oligonucleotides are also useful as mucosal adjuvants. It has previously been discovered that both systemic and mucosal immunity are induced by mucosal delivery of CpG nucleic acids. Thus, the oligonucleotides may be administered in combination with other mucosal adjuvants.

Immune responses can also be induced or augmented by the co-administration or co-linear expression of cytokines (Bueler & Mulligan, 1996; Chow et al., 1997; Geissler et al., 1997; Iwasaki et al., 1997; Kim et al., 1997) or B-7 co-stimulatory molecules (Iwasai et al., 1997; Tsuji et al., 1997) with the CpG immunostimulatory oligonucleotides. The term cytokine is used as a generic name for a diverse group of soluble proteins and peptides which act as humoral regulators at nano- to picomolar concentrations and which, either under normal or pathological conditions, modulate the functional activities of individual cells and tissues. These proteins also mediate interactions between cells directly and regulate processes taking place in the extracellular environment. Examples of cytokines include, but are not limited to IL-1, IL-2, IL-4, IL-5, IL-6, IL-7, IL-10, IL-12, IL-15, IL-18, granulocyte-macrophage colony stimulating factor (GM-CSF), granulocyte colony stimulating factor (G-CSF), interferon-γ (γ-IFN), IFN-α, tumor necrosis factor (TNF), TGF-β, FLT-3 ligand, and CD40 ligand.

The oligonucleotides are also useful for redirecting an immune response from a Th2 immune response to a Th1 immune response. This results in the production of a relatively balanced Th1/Th2 environment. Redirection of an immune response from a Th2 to a Th1 immune response can be assessed by measuring the levels of cytokines produced in response to the nucleic acid (e.g., by inducing monocytic cells and other cells to produce Th1 cytokines, including IL-12, IFN-γ and GM-CSF). The redirection or rebalance of the immune response from a Th2 to a Th1 response is particularly useful for the treatment or prevention of asthma. For instance, an effective amount for treating asthma can be that amount; useful for redirecting a Th2 type of immune response that is associated with asthma to a Th1 type of response or a balanced Th1/Th2 environment. Th2 cytokines, especially IL-4 and IL-5 are elevated in the airways of asthmatic subjects. The CpG immunostimulatory oligonucleotides of the invention cause an increase in Th1 cytokines which helps to rebalance the immune system, preventing or reducing the adverse effects associated with a predominately Th2 immune response.

The oligonucleotides of the invention may also be useful for treating airway remodeling. Airway remodeling results from smooth muscle cell proliferation and/or submucosal thickening in the airways, and ultimately causes narrowing of the airways leading to restricted airflow. The oligonucleotides of the invention may prevent further remodeling and possibly even reduce tissue build up resulting from the remodeling process.

The oligonucleotides are also useful for improving survival, differentiation, activation and maturation of dendritic cells. The CpG immunostimulatory oligonucleotides have the unique capability to promote cell survival, differentiation, activation and maturation of dendritic cells.

CpG immunostimulatory oligonucleotides also increase natural killer cell lytic activity and antibody dependent cellular cytotoxicity (ADCC). ADCC can be performed using a CpG immunostimulatory oligonucleotide in combination with an antibody specific for a cellular target, such as a cancer cell. When the CpG immunostimulatory oligonucleotide is administered to a subject in conjunction with the antibody the subject's immune system is induced to kill the tumor cell. The antibodies useful in the ADCC procedure include antibodies which interact with a cell in the body. Many such antibodies specific for cellular targets have been described in the art and many are commercially available.

The CpG immunostimulatory oligonucleotides may also be administered in conjunction with an anti-cancer therapy. Anti-cancer therapies include cancer medicaments, radiation and surgical procedures. As used herein, a “cancer medicament” refers to a agent which is administered to a subject for the purpose of treating a cancer. As used herein, “treating cancer” includes preventing the development of a cancer, reducing the symptoms of cancer, and/or inhibiting the growth of an established cancer. In other aspects, the cancer medicament is administered to a subject at risk of developing a cancer for the purpose of reducing the risk of developing the cancer. Various types of medicaments for the treatment of cancer are described herein. For the purpose of this specification, cancer medicaments are classified as chemotherapeutic agents, immunotherapeutic agents, cancer vaccines, hormone therapy, and biological response modifiers.

Additionally, the methods of the invention are intended to embrace the use of more than one cancer medicament along with the CpG immunostimulatory oligonucleotides. As an example, where appropriate, the CpG immunostimulatory oligonucleotides may be administered with both a chemotherapeutic agent and an immunotherapeutic agent. Alternatively, the cancer medicament may embrace an immunotherapeutic agent and a cancer vaccine, or a chemotherapeutic agent and a cancer vaccine, or a chemotherapeutic agent, an immunotherapeutic agent and a cancer vaccine all administered to one subject for the purpose of treating a subject having a cancer or at risk of developing a cancer.

The chemotherapeutic agent may be selected from the group consisting of methotrexate, vincristine, adriamycin, cisplatin, non-sugar containing chloroethylnitrosoureas, 5-fluorouracil, mitomycin C, bleomycin, doxorubicin, dacarbazine, taxol, fragyline, Meglamine GLA, valrubicin, carmustaine and poliferposan, MMI270, BAY 12-9566, RAS farnesyl transferase inhibitor, farnesyl transferase inhibitor, MMP, MTA/LY231514, LY264618/Lometexol, Glamolec, CI-994, TNP-470, Hycamtin/Topotecan, PKC412, Valspodar/PSC833, Novantrone/Mitroxantrone, Metaret/Suramin, Batimastat, E7070, BCH-4556, CS-682, 9-AC, AG3340, AG3433, Incel/VX-710, VX-853, ZD0101, ISI641, ODN 698, TA 2516/Marmistat, BB2516/Marmistat, CDP 845, D2163, PD183805, DX8951f, Lemonal DP 2202, FK 317, Picibanil/OK-432, AD 32/Valrubicin, Metastron/strontium derivative, Temodal/Temozolomide, Evacet/liposomal doxorubicin, Yewtaxan/Paclitaxel, Taxol/Paclitaxel, Xeload/Capecitabine, Furtulon/Doxifluridine, Cyclopax/oral paclitaxel, Oral Taxoid, SPU-077/Cisplatin, HMR 1275/Flavopiridol, CP-358 (774)/BGFR, CP-609 (754)/RAS oncogene inhibitor, BMS-182751/oral platinum, UFT(Tegafur/Uracil), Ergamisol/Levamisole, Eniluracil/776C85/5FU enhancer, Campto/Levamisole, Camptosar/Irinotecan, Turnodex/Ralitrexed, Leustatin/Cladribine, Paxex/Paclitaxel, Doxil/liposomal doxorubicin, Caelyz/liposomal doxorubicin, Fludara/Fludarabine, Pharmarubicin/Epirubicin, DepoCyt, ZD1839, LU 79553/Bis-Naphtalimide, LU 103793/Dolastain, Caetyx/liposomal doxorubicin, Gemzar/Gemcitabine, ZD 0473/Anormed, YM 116, Iodine seeds, CDK4 and CDK2 inhibitors, PARP inhibitors, D4809/Dexifosamide, Ifes/Mesnex/Ifosamide, Vumon/Teniposide, Paraplatin/Carboplatin, Plantinol/cisplatin, Vepeside/Etoposide, ZD 9331, Taxotere/Docetaxel, prodrug of guanine arabinoside, Taxane Analog, nitrosoureas, alkylating agents such as melphelan and cyclophosphamide, Aminoglutethimide, Asparaginase, Busulfan, Carboplatin, Chlorombucil, Cytarabine HCl, Dactinomycin, Daunorubicin HCl, Estramustine phosphate sodium, Etoposide (VP16-213), Floxuridine, Fluorouracil (5-FU), Flutamide, Hydroxyurea (hydroxycarbamide), Ifosfamide, Interferon Alfa-2a, Alfa-2b, Leuprolide acetate (LHRH-releasing factor analog), Lomustine (CCNU), Mechlorethamine HCl (nitrogen mustard), Mercaptopurine, Mesna, Mitotane (o,p′-DDD), Mitoxantrone HCl, Octreotide, Plicamycin, Procarbazine HCl, Streptozocin, Tamoxifen citrate, Thioguanine, Thiotepa, Vinblastine sulfate, Amsacrine (m-AMSA), Azacitidine, Erthropoietin, Hexamethylmelamine (HMM), Interleukin 2, Mitoguazone (methyl-GAG; methyl glyoxal bis-guanylhydrazone; MGBG), Pentostatin (2′deoxycoformycin), Semustine (methyl-CCNU), Teniposide (VM-26) and Vindesine sulfate, but it is not so limited.

The immunotherapeutic agent may be selected from the group consisting of Ributaxin, Herceptin, Quadramet, Panorex, IDEC-Y2B8, BEC2, C225, Oncolym, SMART M195, ATRAGEN, Ovarex, Bexxar, LDP-03, ior t6, MDX-210, MDX-11, MDX-22, OV103, 3622 W94, anti-VEGF, Zenapax, MDX-220, MDX-447, MELIMMUNE-2, MELIMMUNE-1, CEACIDE, Pretarget, NovoMAb-G2, TNT, Gliomab-H, GNI-250, EMD-72000, LymphoCide, CMA 676, Monopharm-C, 4B5, ior egf.r3, ior c5, BABS, anti-FLK-2, MDX-260, ANA Ab, SMART 1D10 Ab, SMART ABL 364 Ab and ImmuRAIT-CEA, but it is not so limited.

The cancer vaccine may be selected from the group consisting of EGF, Anti-idiotypic cancer vaccines, Gp75 antigen. GMK melanoma vaccine, MGV ganglioside conjugate vaccine, Her2/neu, Ovarex, M-Vax, O-Vax, L-Vax, STn-KHL theratope, BLP25 (MUC-1), liposomal idiotypic vaccine, Melacine, peptide antigen vaccines, toxin/antigen vaccines, MVA-based vaccine, PACIS, BCG vacine, TA-HPV, TA-CIN, DISC-virus and ImmuCyst/TheraCys, but it is not so limited.

The use of CpG immunostimulatory oligonucleotides in conjunction with immunotherapeutic agents such as monoclonal antibodies is able to increase long-term survival through a number of mechanisms including significant enhancement of ADCC (as discussed above), activation of natural killer (NK) cells and an increase in IFNα levels. The nucleic acids when used in combination with monoclonal antibodies serve to reduce the dose of the antibody required to achieve a biological result.

As used herein, the terms “cancer antigen” and “tumor antigen” are used interchangeably to refer to antigens which are differentially expressed by cancer cells and can thereby be exploited in order to target cancer cells. Cancer antigens are antigens which can potentially stimulate apparently tumor-specific immune responses. Some of these antigens are encoded, although not necessarily expressed, by normal cells. These antigens can be characterized as those which are normally silent (i.e., not expressed) in normal cells, those that are expressed only at certain stages of differentiation and those that are temporally expressed such as embryonic and fetal antigens. Other cancer antigens are encoded by mutant cellular genes, such as oncogenes (e.g., activated as oncogene), suppressor genes (e.g., mutant p53), fusion proteins resulting from internal deletions or chromosomal translocations. Still other cancer antigens can be encoded by viral genes such as those carried on RNA and DNA tumor viruses.

The CpG immunostimulatory oligonucleotides are also useful for treating and preventing autoimmune disease. Autoimmune disease is a class of diseases in which an subject's own antibodies react with host tissue or in which immune effector T cells are autoreactive to endogenous self peptides and cause destruction of tissue. Thus an immune response is mounted against a subject's own antigens, referred to as self antigens. Autoimmune diseases include but are not limited to rheumatoid arthritis, Crohn's disease, multiple sclerosis, systemic lupus erythematosus (SLE), autoimmune encephalomyelitis, myasthenia gravis (MG), Hashimoto's thyroiditis, Goodpasture's syndrome, pemphigus (e.g., pemphigus vulgaris), Grave's disease, autoimmune hemolytic anemia, autoimmune thrombocytopenic purpura, scleroderma with anti-collagen antibodies, mixed connective tissue disease, polymyositis, pernicious anemia, idiopathic Addison's disease, autoimmune-associated infertility, glomerulonephritis (e.g., crescentic glomerulonephritis, proliferative glomerulonephritis), bullous pemphigoid. Sjögren's syndrome, insulin resistance, and autoimmune diabetes mellitus.

A “self-antigen” as used herein refers to an antigen of a normal host tissue. Normal host tissue does not include cancer cells. Thus an immune response mounted against a self-antigen, in the context of an autoimmune disease, is an undesirable immune response and contributes to destruction and damage of normal tissue, whereas an immune response mounted against a cancer antigen is a desirable immune response and contributes to the destruction of the tumor or cancer. Thus, in some aspects of the invention aimed at treating autoimmune disorders it is not recommended that the CpG immunostimulatory nucleic acids be administered with self antigens, particularly those that are the targets of the autoimmune disorder.

In other instances, the CpG immunostimulatory nucleic acids may be delivered with low doses of self-antigens. A number of animal studies have demonstrated that mucosal administration of low doses of antigen can result in a state of immune hyporesponsiveness or “tolerance.” The active mechanism appears to be a cytokine-mediated immune deviation away from a Th1 towards a predominantly Th2 and Th3 (i.e., TGF-β dominated) response. The active suppression with low dose antigen delivery can also suppress an unrelated immune response (bystander suppression) which is of considerable interest in the therapy of autoimmune diseases, for example, rheumatoid arthritis and SLE. Bystander suppression involves the secretion of Th1-counter-regulatory, suppressor cytokines in the local environment where proinflammatory and Th1 cytokines are released in either an antigen-specific or antigen-nonspecific manner. “Tolerance” as used herein is used to refer to this phenomenon. Indeed, oral tolerance has been effective in the treatment of a number of autoimmune diseases in animals including: experimental autoimmune encephalomyelitis (EAE), experimental autoimmune myasthenia gravis, collagen-induced arthritis (CIA), and insulin-dependent diabetes mellitus. In these models, the prevention and suppression of autoimmune disease is associated with a shift in antigen-specific humoral and cellular responses from a Th1 to Th2/Th3 response.

The invention also includes a method for inducing antigen non-specific innate immune activation and broad spectrum resistance to infectious challenge using the CpG immunostimulatory oligonucleotides. The term antigen non-specific innate immune activation as used herein refers to the activation of immune cells other than B cells and for instance can include the activation of NK cells, T cells or other immune cells that can respond in an antigen independent fashion or some combination of these cells. A broad spectrum resistance to infectious challenge is induced because the immune cells are in active form and are primed to respond to any invading compound or microorganism. The cells do not have to be specifically primed against a particular antigen. This is particularly useful in biowarfare, and the other circumstances described above such as travelers.

The CpG immunostimulatory oligonucleotides may be directly administered to the subject or may be administered in conjunction with a nucleic acid delivery complex. A nucleic acid delivery complex shall mean a nucleic acid molecule associated with (e.g. ionically or covalently bound to; or encapsulated within) a targeting means (e.g. a molecule that results in higher affinity binding to target cell. Examples of nucleic acid delivery complexes include nucleic acids associated with a sterol (e.g. cholesterol), a lipid (e.g. a cationic lipid, virosome or liposome), or a target cell specific binding agent (e.g. a ligand recognized by target cell specific receptor). Preferred complexes may be sufficiently stable in vivo to prevent significant uncoupling prior to internalization by the target cell. However, the complex can be cleavable under appropriate conditions within the cell so that the oligonucleotide is released in a functional form.

Delivery vehicles or delivery devices for delivering antigen and oligonucleotides to surfaces have been described. The CpG immunostimulatory oligonucleotide and/or the antigen and/or other therapeutics may be administered alone (e.g., in saline or buffer) or using any delivery vehicles known in the art. For instance the following delivery vehicles have been described: Cochleates; Emulsomes, ISCOMs; Liposomes; Live bacterial vectors (e.g., Salmonella, Escherichia coli, Bacillus calmatte-guerin, Shigella, Lactobacillus); Live viral vectors (e.g., Vaccinia, adenovirus, Herpes Simplex); Microspheres; Nucleic acid vaccines; Polymers; Polymer rings; Proteosomes; Sodium Fluoride; Transgenic plants; Virosomes; Virus-like particles. Other delivery vehicles are known in the art and some additional examples are provided below in the discussion of vectors.

The term effective amount of a CpG immunostimulatory oligonucleotide refers to the amount necessary or sufficient to realize a desired biologic effect. For example, an effective amount of a CpG immunostimulatory oligonucleotide administered with an antigen for inducing mucosal immunity is that amount necessary to cause the development of IgA in response to an antigen upon exposure to the antigen, whereas that amount required for inducing systemic immunity is that amount necessary to cause the development of IgG in response to an antigen upon exposure to the antigen. Combined with the teachings provided herein, by choosing among the various active compounds and weighing factors such as potency, relative bioavailability, patient body weight, severity of adverse side-effects and preferred mode of administration, an effective prophylactic or therapeutic treatment regimen can be planned which does not cause substantial toxicity and yet is entirely effective to treat the particular subject. The effective amount for any particular application can vary depending on such factors as the disease or condition being treated, the particular CpG immunostimulatory oligonucleotide being administered the size of the subject, or the severity of the disease or condition. One of ordinary skill in the art can empirically determine the effective amount of a particular CpG immunostimulatory olignucleotide and/or antigen and/or other therapeutic agent without necessitating undue experimentation.

Subject doses of the compounds described herein for mucosal or local delivery typically range from about 0.1 g to 10 mg per administration, which depending on the application could be given daily, weekly, or monthly and any other amount of time therebetween. More typically mucosal or local doses range from about 10 μg to 5 mg per administration, and most typically from about 100 μg to 1 mg, with 2-4 administrations being spaced days or weeks apart. More typically, immune stimulant doses range from 1 μg to 10 mg per administration, and most typically 10 μg to 1 mg, with daily or weekly administrations. Subject doses of the compounds described herein for parenteral delivery for the purpose of inducing an antigen-specific immune response, wherein the compounds are delivered with an antigen but not another therapeutic agent are typically 5 to 10,000 times higher than the effective mucosal dose for vaccine adjuvant or immune stimulant applications, and more typically 10 to 1,000 times higher, and most typically 20 to 100 times higher. Doses of the compounds described herein for parenteral delivery for the purpose of inducing an innate immune response or for increasing ADCC or for inducing an antigen specific immune response when the CpG immunostimulatory oligonucleotides are administered in combination with other therapeutic agents or in specialized delivery vehicles typically range from about 0.1 μg to 10 mg per administration, which depending on the application could be given daily, weekly, or monthly and any other amount of time therebetween. More typically parenteral doses for these purposes range from about 10 μg to 5 mg per administration, and most typically from about 100 μg to 1 mg, with 2-4 administrations being spaced days or weeks apart. In some embodiments, however, parenteral doses for these purposes may be used in a range of 5 to 10,000 times higher than the typical doses described above.

For any compound described herein the therapeutically effective amount can be initially determined from animal models. A therapeutically effective dose can also be determined from human data for CpG oligonucleotides which have been tested in humans (human clinical trials have been initiated) and for compounds which are known to exhibit similar pharmacological activities, such as other adjuvants, e.g., LT and other antigens for vaccination purposes. Higher doses may be required for parenteral administration. The applied dose can be adjusted based on the relative bioavailability and potency of the administered compound. Adjusting the dose to achieve maximal efficacy based on the methods described above and other methods as are well-known in the art is well within the capabilities of the ordinarily skilled artisan.

The formulations of the invention are administered in pharmaceutically acceptable solutions, which may routinely contain pharmaceutically acceptable concentrations of salt, buffering agents, preservatives, compatible carriers, adjuvants, and optionally other therapeutic ingredients.

For use in therapy, an effective amount of the CpG immunostimulatory oligonucleotide can be administered to a subject by any mode that delivers the oligonucleotide to the desired surface, e.g., mucosal, systemic. Administering the pharmaceutical composition of the present invention may be accomplished by any means known to the skilled artisan. Preferred routes of administration include but are not limited to oral, parenteral, intramuscular, intranasal, sublingual, intratracheal, inhalation, ocular, vaginal, and rectal.

For oral administration, the compounds (i.e., CpG immunostimulatory oligonucleotides, antigens and other therapeutic agents) can be formulated readily by combining the active compound(s) with pharmaceutically acceptable carriers well known in the art. Such carriers enable the compounds of the invention to be formulated as tablets, pills, dragees capsules, liquids, gels, syrups, slurries, suspensions and the like, for oral ingestion by a subject to be treated. Pharmaceutical preparations for oral use can be obtained as solid excipient, optionally grinding a resulting mixture, and processing the mixture of granules, after adding suitable auxiliaries, if desired, to obtain tablets or dragee cares. Suitable excipients are, in particular, fillers such as sugars, including lactose, sucrose, mannitol, or sorbitol; cellulose preparations such as, for example, maize starch, wheat starch, rice starch, potato starch, gelatin, gum tragacanth, methyl cellulose, hydroxypropylmethyl-cellulose, sodium carboxymethylcellulose, and/or polyvinylpyrrolidone (PVP). If desired, disintegrating agents may be added, such as the cross-linked polyvinyl pyrrolidone, agar, or alginic acid or a salt thereof such as sodium alginate. Optionally the oral formulations may also be formulated in saline or buffers, i.e. EDTA for neutralizing internal acid conditions or may be administered without any carriers.

Also specifically contemplated are oral dosage forms of the above component or components. The component or components may be chemically modified so that oral delivery of the derivative is efficacious. Generally, the chemical modification contemplated is the attachment of at least one moiety to the component molecule itself where said moiety permits (a) inhibition of proteolysis; and (b) uptake into the blood stream from the stomach or intestine. Also desired is the increase in overall stability of the component or components and increase in circulation time in the body. Examples of such moieties include: polyethylene glycol, copolymers of ethylene glycol and propylene glycol, carboxymethyl cellulose, dextran, polyvinyl alcohol, polyvinyl pyrrolidone and polyproline. Abuchowski and Davis, 1981, “Soluble Polymer-Enzyme Adducts” In: Enzymes as Drugs, Hocenberg and Roberts, eds., Wiley-Interscience, New York, N.Y., pp. 367-383; Newmark, et al., 1982, J. Appl. Biochem. 4:185-189. Other polymers that could be used are poly-1,3-dioxolan and poly-1,3,6-tioxocane. Preferred for pharmaceutical usage, as indicated above, are polyethylene glycol moieties.

For the component (or derivative) the location of release may be the stomach, the small intestine (the duodenum, the jejunum, or the ileum), or the large intestine. One skilled in the art has available formulations which will not dissolve in the stomach, yet will release the material in the duodenum or elsewhere in the intestine. Preferably, the release will avoid the deleterious effects of the stomach environment, either by protection of the oligonucleotide (or derivative) or by release of the biologically active material beyond the stomach environment, such as in the intestine.

To ensure full gastric resistance a coating impermeable to at least pH 5.0 is essential. Examples of the more common inert ingredients that are used as enteric coatings are cellulose acetate trimellitate (CAT), hydroxypropylmethylcellulose phthalate (HPMCP), HPMCP 50, HPMCP 55, polyvinyl acetate phthalate (PVAP), Eudragit L30D, Aquateric, cellulose acetate phthalate (CAP), Eudragit L, Eudragit S, and Shellac. These coatings may be used as mixed films.

A coating or mixture of coatings can also be used on tablets, which are not intended for protection against the stomach. This can include sugar coatings, or coatings which make the tablet easier to swallow. Capsules may consist of a hard shell (such as gelatin) for delivery of dry therapeutic i.e. powder, for liquid forms, a soft gelatin shell may be used. The shell material of cachets could be thick starch or other edible paper. For pills, lozenges, molded tablets or tablet triturates, moist massing techniques can be used.

The therapeutic can be included in the formulation as fine multi-particulates in the form of granules or pellets of particle size about 1 nm. The formulation of the material for capsule administration could also be as a powder, lightly compressed plugs or even as tablets. The therapeutic could be prepared by compression.

Colorants and flavoring agents may all be included. For example, the oligonucleotide (or derivative) may be formulated (such as by liposome or microsphere encapsulation) and then further contained within an edible product, such as a refrigerated beverage containing colorants and flavoring agents.

One may dilute or increase the volume of the therapeutic with an inert material. These diluents could include carbohydrates, especially mannitol, a-lactose, anhydrous lactose, cellulose, sucrose, modified dextrans and starch. Certain inorganic salts may be also be used as fillers including calcium triphosphate magnesium carbonate and sodium chloride. Some commercially available diluents are Fast-Flo, Emdex, STA-Rx 1500, Emcompress and Avicell.

Disintegrants may be included in the formulation of the therapeutic into a solid dosage form. Materials used as disintegrates include but are not limited to starch, including the commercial disintegrant based on starch, Explotab. Sodium starch glycolate, Amberlite, sodium carboxymethylcellulose, ultramylopectin, sodium alginate, gelatin, orange peel, acid carboxymethyl cellulose, natural sponge and bentonite may all be used. Another form of the disintegrants are the insoluble cationic exchange resins. Powdered gums may be used as disintegrants and as binders and these can include powdered gums such as agar, Karaya or tragacanth. Alginic acid and its sodium salt are also useful as disintegrants.

Binders may be used to hold the therapeutic agent together to form a hard tablet and include materials from natural products such as acacia, tragacanth, starch and gelatin. Other include methyl cellulose (MC), ethyl cellulose (BC) and carboxymethyl cellulose (CMC). Polyvinyl pyrrolidone (PVP) and hydroxypropylmethyl cellulose (HPMC) could both be used in alcoholic solutions to granulate the therapeutic.

An anti-frictional agent may be included in the formulation of the therapeutic to prevent sticking during the formulation process. Lubricants may be used as a layer between the therapeutic and the die wall, and these can include but are not limited to; stearic acid including its magnesium and calcium salts, polytetrafluoroethylene (PTFE), liquid paraffin, vegetable oils and waxes. Soluble lubricants may also be used such as sodium lauryl sulfate, magnesium lauryl sulfate, polyethylene glycol of various molecular weights, Carbowax 4000 and 6000.

Glidants that might improve the flow properties of the drug during formulation and to aid rearrangement during compression might be added. The glidants may include starch, talc, pyrogenic silica and hydrated silicoaluminate.

To aid dissolution of the therapeutic into the aqueous environment a surfactant might be added as a wetting agent. Surfactants may include anionic detergents such as sodium lauryl sulfate, dioctyl sodium sulfosuccinate and dioctyl sodium sulfonate. Cationic detergents might be used and could include benzalkonium chloride or benzethomium chloride. The list of potential nonionic detergents that could be included in the formulation as surfactants are lauromacrogol 400, polyoxyl 40 stearate, polyoxyethylene hydrogenated castor oil 10, 50 and 60, glycerol monosterate, polysorbate 40, 60, 65 and 80, sucrose fatty acid ester, methyl cellulose and carboxymethyl cellulose. These surfactants could be present in the formulation of the oligonucleotide or derivative either alone or as a mixture in different ratios.

Pharmaceutical preparations which can be used orally include push-fit capsules made of gelatin, as well as soft, sealed capsules made of gelatin and a plasticizer, such as glycerol or sorbitol. The push-fit capsules can contain the active ingredients in admixture with filler such as lactose, binders such as starches, and/or lubricants such as talc or magnesium stearate and, optionally, stabilizers. In soft capsules, the active compounds may be dissolved or suspended in suitable liquids, such as fatty oils, liquid paraffin, or liquid polyethylene glycols. In addition, stabilizers may be added. Microspheres formulated for oral administration may also be used. Such microspheres have been well defined in the art. All formulations for oral administration should be in dosages suitable for such administration.

For buccal administration, the compositions may take the form of tablets or lozenges formulated in conventional manner.

For administration by inhalation, the compounds for use according to the present invention may be conveniently delivered in the form of an aerosol spray presentation from pressurized packs or a nebulizer, with the use of a suitable propellant, e.g., dichlorodifluoromethane, trichlorofluoromethane, dichlorotetrafluoroethane, carbon dioxide or other suitable gas. In the case of a pressurized aerosol the dosage unit may be determined by providing a valve to deliver a metered amount. Capsules and cartridges of e.g. gelatin for use in an inhaler or insufflator may be formulated containing a powder mix of the compound and a suitable powder base such as lactose or starch.

Also contemplated herein is pulmonary delivery of the oligonucleotides (or derivatives thereof). The oligonucleotide (or derivative) is delivered to the lungs of a mammal while inhaling and traverses across the lung epithelial lining to the blood stream. Other reports of inhaled molecules include Adjei et al., 1990, Pharmaceutical Research, 7:565-569; Adjei et al., 1990, International Journal of Pharmaceutics, 63:135-144 (leuprolide acetate); Braquet et al., 1989, Journal of Cardiovascular Pharmacology, 13(suppl. 5):143-146 (endothelin-1); Hubbard et al., 1989, Annals of Internal Medicine, Vol. III, pp. 206-212 (al-antitrypsin); Smith et al., 1989, J. Clin. Invest. 84:1145-1146 (a-1-proteinase); Oswein et al., 1990, “Aeosolization of Proteins”, Proceedings of Symposium on Respiratory Drug Delivery II, Keystone, Colo., March, (recombinant human growth hormone); Debs et al., 1988, J. Immunol. 140:3482-3488 (interferon-g and tumor necrosis factor alpha) and Platz et al, U.S. Pat. No. 5,284,656 (granulocyte colony stimulating actor). A method and composition for pulmonary delivery of drugs for systemic effect is described in U.S. Pat. No. 5,451,569, issued Sep. 19, 1995 to Wong et al.

Contemplated for use in the practice of this invention are a wide range of mechanical devices designed for pulmonary delivery of therapeutic products, including but not limited to nebulizers, metered dose inhales, and powder inhalers, all of which are familiar to those skilled in the art.

Some specific examples of commercially available devices suitable for the practice of this invention are the Ultravent nebulizer, manufactured by Mallinckrodt, Inc., St. Louis, Mo.; the Acorn II nebulizer, manufactured by Marquest Medical Products, Englewood, Colo.; the Ventolin metered dose inhaler, manufactured by Glaxo Inc., Research Triangle Park, North Carolina; and the Spinhaler powder inhaler, manufactured by Fisons Corp., Bedford, Mass.

All such devices require the use of formulations suitable for the dispensing of oligonucleotide (or derivative). Typically, each formulation is specific to the type of device employed and may involve the use of an appropriate propellant material, in addition to the usual diluents, adjuvants and/or carriers useful in therapy. Also, the use of liposomes, microcapsules or microspheres, inclusion complexes, or other types of carriers is contemplated. Chemically modified oligonucleotide may also be prepared in different formulations depending on the type of chemical modification or the type of device employed.

Formulations suitable for use with a nebulizer, either jet or ultrasonic, will typically comprise oligonucleotide (or derivative) dissolved in water at a concentration of about 0.1 to 25 mg of biologically active oligonucleotide per mL of solution. The formulation may also include a buffer and a simple sugar (e.g., for oligonucleotide stabilization and regulation of osmotic pressure). The nebulizer formulation may also contain a surfactant, to reduce or prevent surface induced aggregation of the oligonucleotide caused by atomization of the solution in forming the aerosol.

Formulations for use with a metered-dose inhaler device will generally comprise a finely divided powder containing the oligonucleotide (or derivative) suspended in a propellant with the aid of a surfactant. The propellant may be any conventional material employed for this purpose, such as a chlorofluorocarbon, a hydrochlorofluorocarbon, a hydrofluorocarbon, or a hydrocarbon, including trichlorofluoromethane, dichlorodifluoromethane, di and 1,1,1,2-tetrafluoroethane, or combinations thereof. Suitable surfactants include sorbitan trioleate and soya lecithin. Oleic acid may also be useful as a surfactant.

Formulations for dispensing from a powder inhaler device will comprise a finely divided dry powder containing oligonucleotide (or derivative) and may also include a bulking agent such as lactose, sorbitol, sucrose, or mannitol in amounts which facilitate dispersal of the powder from the device, e.g., 50 to 90% by weight of the formulation. The oligonucleotide (or derivative) should most advantageously be prepared in particulate form with an average particle size of less than 10 mm (or microns), most preferably 0.5 to 5 mm, for most effective delivery to the distal lung.

Nasal delivery of a pharmaceutical composition of the present invention is also contemplated. Nasal delivery allows the passage of a pharmaceutical composition of the present invention to the blood stream directly after administering the therapeutic product to the nose, without the necessity for deposition of the product in the lung. Formulations for nasal delivery include those with dextran or cyclodextran.

For nasal administration, a useful device is a small, hard bottle to which a metered dose sprayer is attached. In one embodiment, the metered dose is delivered by drawing the pharmaceutical composition of the present invention solution into a chamber of defined volume, which chamber has an aperture dimensioned to aerosolize and aerosol formulation by forming a spray when a liquid in the chamber is compressed. The chamber is compressed to administer the pharmaceutical composition of the present invention. In a specific embodiment, the chamber is a piston arrangement. Such devices are commercially available.

Alternatively, a plastic squeeze bottle with an aperture or opening dimensioned to aerosolize an aerosol formulation by forming a spray when squeezed is used. The opening is usually found in the top of the bottle, and the top is generally tapered to partially fit in the nasal passages for efficient administration of the aerosol formulation. Preferably, the nasal inhaler will provide a metered amount of the aerosol formulation, for administration of a measured dose of the drug.

The compounds, when it is desirable to deliver them systemically, may be formulated for parenteral administration by injection, e.g., by bolus injection or continuous infusion. Formulations for injection may be presented in unit dosage form, e.g., in ampoules or in multi-dose containers, with an added preservative. The compositions may take such forms as suspensions, solutions or emulsions in oily or aqueous vehicles, and may contain formulatory agents such as suspending, stabilizing and/or dispersing agents.

Pharmaceutical formulations for parenteral administration include aqueous solutions of the active compounds in water-soluble form. Additionally, suspensions of the active compounds may be prepared as appropriate oily injection suspensions. Suitable lipophilic solvents or vehicles include fatty oils such as sesame oil, or synthetic fatty acid esters, such as ethyl oleate or triglycerides, or liposomes. Aqueous injection suspensions may contain substances which increase the viscosity of the suspension, such as sodium carboxymethyl cellulose, sorbitol, or dextran. Optionally, the suspension may also contain suitable stabilizers or agents which increase the solubility of the compounds to allow for the preparation of highly concentrated solutions.

Alternatively, the active compounds may be in powder form for constitution with a suitable vehicle, e.g., sterile pyrogen-free water, before use.

The compounds may also be formulated in rectal or vaginal compositions such as suppositories or retention enemas, e.g., containing conventional suppository bases such as cocoa butter or other glycerides.

In addition to the formulations described previously, the compounds may also be formulated as a depot preparation. Such long acting formulations may be formulated with suitable polymeric or hydrophobic materials (for example as an emulsion in an acceptable oil) or ion exchange resins, or as sparingly soluble derivatives, for example, as a sparingly soluble salt.

The pharmaceutical compositions also may comprise suitable solid or gel phase carriers or excipients. Examples of such carriers or excipients include but are not limited to calcium carbonate, calcium phosphate, various sugars, starches, cellulose derivatives, gelatin, and polymers such as polyethylene glycols.

Suitable liquid or solid pharmaceutical preparation forms are, for example, aqueous or saline solutions for inhalation, microencapsulated, encochleated, coated onto microscopic gold particles, contained in liposomes, nebulized, aerosols, pellets for implantation into the skin, or dried onto a sharp object to be scratched into the skin. The pharmaceutical compositions also include granules, powders, tablets, coated tablets, (micro)capsules, suppositories, syrups, emulsions, suspensions, creams, drops or preparations with protracted release of active compounds, in whose preparation excipients and additives and/or auxiliaries such as disintegrants, binders, coating agents, swelling agents lubricants, flavorings, sweeteners or solubilizers are customarily used as described above. The pharmaceutical compositions are suitable for use in a variety of drug delivery systems. For a brief review of methods for drug delivery, see Langer, Science 249:1527-1533, 1990, which is incorporated herein by reference.

The CpG immunostimulatory oligonucleotides and optionally other therapeutics and/or antigens may be administered per se (neat) or in the form of a pharmaceutically acceptable salt. When used in medicine the salts should be pharmaceutically acceptable, but non-pharmaceutically acceptable salts may conveniently be used to prepare pharmaceutically acceptable salts thereof. Such salts include, but are not limited to, those prepared from the following acids: hydrochloric, hydrobromic, sulphuric, nitric, phosphoric, maleic, acetic, salicylic, p-toluene sulphonic, tartaric, citric, methane sulphonic, formic, malonic, succinic, naphthalene-2-sulphonic, and benzene sulphonic. Also, such salts can be prepared as alkaline metal or alkaline earth salts, such as sodium, potassium or calcium salts of the carboxylic acid group.

Suitable buffering agents include: acetic acid and a salt (1-2% w/v); citric acid and a salt (1-3% w/v); boric acid and a salt (0.5-2.5% w/v); and phosphoric acid and a salt (0.8-2% w/v). Suitable preservatives include benzalkonium chloride (0.003-0.03% w/v); chlorobutanol (0.3-0.9% w/v); parabens (0.01-0.25% w/v) and thimerosal (0.004-0.02% w/v).

The pharmaceutical compositions of the invention contain an effective amount of a CpG immunostimulatory oligonucleotide and optionally antigens and/or other therapeutic agents optionally included in a pharmaceutically-acceptable carrier. The term pharmaceutically-acceptable carrier means one or more compatible solid or liquid filler, diluents or encapsulating substances which are suitable for administration to a human or other vertebrate animal. The term carrier denotes an organic or inorganic ingredient, natural or synthetic, with which the active ingredient is combined to facilitate the application. The components of the pharmaceutical compositions also are capable of being commingled with the compounds of the present invention, and with each other, in a manner such that there is no interaction which would substantially impair the desired pharmaceutical efficiency.

The present invention is further illustrated by the following Examples, which in no way should be construed as further limiting. The entire contents of all of the references (including literature references, issued patents, published patent applications, and co-pending patent applications) cited throughout this application are hereby expressly incorporated by reference.

EXAMPLES Materials and Methods Oligodeoxynucleotides (ODN) and Reagents

All ODN were synthesized following standard phosphoramidite chemistry protocols and controlled for identity and purity by Coley Pharmaceutical GmbH and had undetectable endotoxin levels (<0.1 EU/ml) measured by the Limulus assay (BioWhittaker, Verviers, Belgium). ODN were suspended in sterile, endotoxin-free Tris-EDTA (Sigma, Deisenhofen, Germany), and stored and handled under aseptic conditions to prevent both microbial and endotoxin contamination. All dilutions were carried out using endotoxin-free Tris-EDTA.

TLR Assays

HEK293 cells were transfected by electroporation with vectors expressing the respective human TLR and a 6×NF-κB-luciferase reporter plasmid. Stable transfectants (3×10⁴ cells/well) were incubated indicated amounts of ODN for 16 h at 37° C. in a humidified incubator. Each data point was done in triplicate. Cells were lysed and assayed for luciferase gene activity (using the BriteLite kit from Perkin-Elmer, Zaventem, Belgium). Stimulation indices were calculated in reference to reporter gene activity of medium without addition of ODN.

Cell Purification

Peripheral blood buffy coat preparations from healthy human donors were obtained from the Blood Bank of the University of Düsseldorf (Germany) and PBMC were purified by centrifugation over Ficoll-Hypaque (Sigma). Cells were cultured in a humidified incubator at 37° C. in RPMI 1640 medium supplemented with 5% (v/v) heat inactivated human AB serum (BioWhittaker) or 10% (v/v) heat inactivated FCS, 2 mM L-glutamine, 100 U/ml penicillin and 100 μg/ml streptomycin (all from Sigma).

Cytokine Detection and Flow Cytometric Analysis

PBMC were resuspended at a concentration of 5×10 cells/ml and added to 96 well round-bottomed plates (250 μl/well). PBMC were incubated with ODN and culture supernatants (SN) were collected after the indicated time points. If not used immediately, SN were stored at −20° C. until required.

Amounts of cytokines in the SN were assessed using an in-house ELISA for IFN-α developed using commercially available antibody (PBL, New Brunswick, N.J., USA) or on the Luminex multiplex system (Lumninex Corporation, 12212 Technology Boulevard, Austin, Tex. 78727-6115).

Animals

Female BALB/c mice (6-8 weeks of age) were purchased from Charles River Canada (Quebec, Canada) and housed in micro-isolators in the Animal Care Facility at Coley Pharmaceutical Group Canada. All studies were conducted in accordance with the Animal Care Committee of Coley Canada under the guidance of the Canadian Council on Animal Care. All animals were naïve to CpG ODNs.

SA1N tumor model: Female A/J mice (10 per group) were injected SC with 5×10⁵ SaI/N tumor cells on day 0. Mice were treated with 100 μg ODN or PBS alone given SC once weekly starting on day 8 post tumor induction. Animals were monitored for survival and tumor volume. Tumor size (the length and the width) was measured using a digital vernier caliper. Tumor volume was calculated by using the formula: Tumor volume=(0.4)(ab2), where a=large diameter and b=smaller diameter.

In Vitro Assays

Naïve BALB/c mouse splenocytes (from pools of 3-5 animals) were used for in vitro assays. Animals were anaesthetized with isoflurane and euthanized by cervical dislocation. Spleens were removed under aseptic conditions and placed in PBS+0.2% bovine serum albumin (Sigma Chemical Company) Spleens were then homogenized and splenocytes were re-suspended in RPMI 1640 (Life Technologies, Grand Island, N.Y.) tissue culture medium supplemented with 2% normal mouse serum (Cedarlane Laboratories, Ontario, Canada), penicillin-streptomycin solution (final concentration of 1000 U/ml and 1 mg/ml respectively, Sigma Chemical Company), and 5×10−5 M b-mercaptoethanol (Sigma Chemical Company).

B Cell Proliferation Assays

Caboxy-florescein diacetate, succimidyl ester (CFSE) (Invitrogen, Eugene, Oreg., USA) stained BALB/c mouse splenocytes (4×10⁵/well) were incubated with different concentrations of ODN in a humidified 5% CO₂ incubator at 37° C. for 5 days. Cells were then stained with PE conjugated anti-CD19 antibody (BD Pharmingen, San Diego, Calif., USA) for CD19 and B-cell proliferation was determined by FACS followed by analysis by ModFit Software V3.0 (Verity Software House Inc., Topsham, Me., USA).

Example 1 Investigation of Structure Activity Relationship at the CpG Motif

It is known that oligonucleotides containing unmethylated CpG motifs are able to stimulate immune responses through the Toll-like receptor 9 (TLR9) pathway. In order to identify oligonucleotides with the greatest ability to stimulate the TLR9 pathway, comprehensive structure activity relationship (SAR) study at the CpG motif was performed. The results showed that substitution of guanine by hypoxanthine and 6-thioguanine leads to a similar activity in hTLR9 assay, while purine, 2-aminopurine, 2,6-diaminopurine, 8-oxo-7,8-dihydroguanine and 7-deazaguanine substitution resulted in a 40-80% reduction in hTLR9 stimulation. Further, modification at C5 and N4 resulted in no stimulation of the hTLR9 pathway. These observations resulted in a SAR model in which guanine is recognized via the Hoogsteen site while cytosine binds at the C,H-Edge to the TLR9 receptor (see FIG. 1a ). Thus, no modification at the Hoogsteen recognition site of guanine as well as the C,H-edge of the cytosine was possible without significant loss in hTLR9 activity. None of the investigated base modifications at the dinucleotide motif was more active than the unmodified CpG motif.

Example 2 The Effect of Hydrophobic Thymine Base Shape Analogs Near the CpG Motif

To investigate the impact of the dT residues in neighborhood to the CpG motif several hydrophobic thymine base shape analogs, such as 2,4-difluorotoluene (FF) (SEQ ID NO:3-9), 5-bromo-2′-deoxyuridine (BU) and 5-iodo-2′-deoxyuridine (JU), were incorporated outside of the CpG motif (see Table 1 and FIGS. 2-3). Surprisingly, incorporation of all tested hydrophobic thymine analogs led to an unusually strong increase in hTLR9 activity, while substitution by uracil residues (thymine with lacking methyl group, FIG. 4) led to a sang decrease in hTLR9 stimulation. The increase in TLR9 stimulation was pronounced when the modification was 5′ to the CpG motif Double substitution with 5-iodouracil (JU) 5′ and 3′ of the CpG motif resulted in most potent stimulation of those tested. In contrast, substitution of guanine and cytosine by 2,4-difluorotoluene at the CpG motif led in both cases to a strong decrease of the TLR9 stimulation index.

Incorporation of hydrophobic T analogs also resulted in a strong enhancement of IFN-alpha induction in human PBMCs. Unexpectedly, modification of an ODN (SEQ ID NO:1) that is virtually inactive in inducing IFN-alpha with 5-bromouridine and 5-iodouridine in particular resulted in increased TLR9 stimulation and IFN-alpha induction. There is usually an inverse correlation between TLR9 and IFN-alpha induction for CpG ODN which do not contain these modifications.

TABLE 1 Examples of modified oligonucleotides with hydrophobic thymine base shape analogs near the CpG motif Seq ID Description/ No# Oligonucleotide sequence class derived from  1 T*G*T*C-G*T*T*T*T*T*T*T*T*T*T*T*T*T*T*T 1xPO of SEQ ID NO: 2  2 T*G*T*C*G*T*T*T*T*T*T*T*T*T*T*T*T*T*T*T  3 T*G*FF*C-G*T*T*T*T*T*T*T*T*T*T*T*T*T*T*T 5′FF derivative of SEQ ID NO: 1  4 T*G*T*C-G*FF*T*T*T*T*T*T*T*T*T*T*T*T*T*T 3′FF derivative of SEQ ID NO: 1  5 T*G*FF*C-G*FF*T*T*T*T*T*T*T*T*T*T*T*T*T*T 3′ and 5′FF derivative of  SEQ ID NO: 1  6 T*G*T*FF-G*T*T*T*T*T*T*T*T*T*T*T*T*T*T*T C->FF  7 T*G*T*C-FF*T*T*T*T*T*T*T*T*T*T*T*T*T*T*T G->FF  8 T*FF*C-G*T*T*T*T*T*T*T*T*T*T*T*T*T*T*T*T GT->FF  9 T*G*T*C-G*T*FF*T*T*T*T*T*T*T*T*T*T*T*T*T 3′FF derivative of SEQ ID NO: 1 10 T*G*BU*C-G*T*T*T*T*T*T*T*T*T*T*T*T*T*T*T 5′BU derivative of SEQ ID NO: 1 11 T*G*T*C-G*BU*T*T*T*T*T*T*T*T*T*T*T*T*T*T 3′BU derivative of SEQ ID NO: 1 12 T*G*BU*C-G*BU*T*T*T*T*T*T*T*T*T*T*T*T*T*T 3′ and 5′BU derivative of  SEQ ID NO: 1 13 T*G*JU*C-G*T*T*T*T*T*T*T*T*T*T*T*T*T*T*T 5′JU of SEQ ID NO: 1 14 T*G*T*C-G*JU*T*T*T*T*T*T*T*T*T*T*T*T*T*T 3′JU of SEQ ID NO: 1 15 T*G*JU*C-G*JU*T*T*T*T*T*T*T*T*T*T*T*T*T*T 3′ and 5′JU derivative of  SEQ ID NO: 1 16 T*G*U*C-G*T*T*T*T*T*T*T*T*T*T*T*T*T*T*T 5′U derivative of SEQ ID NO: 1 17 T*G*T*C-G*U*T*T*T*T*T*T*T*T*T*T*T*T*T*T 3′U derivative of SEQ ID NO: 1 18 T*G*U*C-G*U*T*T*T*T*T*T*T*T*T*T*T*T*T*T 3′ and 5′U derivative of  SEQ ID NO: 1 *phosphorothioate internucleotide linkage -phosphodiester internucleotide linkage

Example 3 Activation of TLR9 with Lipophilic Base Shape Substitution

Since different types of lipophilic substitution of the base 5′ to the CpG motif caused significant increases in stimulation of hTLR9, other base analogs, such as 5-chloro-uracil, 5-trifluoromethyl-uracil, phenyl, aryl and substituted aryl residues were investigated for their ability to stimulate hTLR9 (Table 3). To investigate activation of human TLR9 by B-class oligonucleotides modified with various lipophilic base analogs, B-class ODN SEQ ID NO:1 was modified with 5-Chloro-2′-deoxyuridine (CU), 5-Bromo-2′-deoxyuridine (BU), 5-Iodo-2′-deoxyuridine (JU) and 5-Ethyl-2′-deoxyuridine (EU). hTLR9-NFkB-293 cells were incubated with the indicated ODN (FIG. 5a ) for 16 hours. Cells were then lysed and luciferase activity was determined. CU-modified (SEQ ID NO:41), BU-modified (SEQ ID NO:10) JU-modified (SEQ ID NO:13) and EU-modified (SEQ ID NO:42) oligonucleotides all showed greater stimulation of TLR9 activity over control (SEQ ID NO:1). SEQ ID NO:16 with uridine modification showed dramatically decreased activity. In a second experiment IFN-alpha production was measured (FIG. 5b ). Human PBMC were incubated with the modified ODN as indicated for 24 h, after which the supernatants were tested by ELISA. JU-modified, BU-modified, and EU-modified ODN resulted in the greatest increase in IFN-alpha over control. These data demonstrate that 5′-substitution of dU on a B-class ODN increases TLR9 activity and IFN-alpha production.

To further investigate the effect of EU modification on TLR9 activation, the experiment was repeated with modified oligonucleotides having EU modifications 5′ of the CpG (SEQ ID NO:42). 3′ of the CpG (SEQ ID NO:29), and 5′ and 3′ of the CG (SEQ ID NO:30). SEQ ID NOs 42 and 30 showed a significant increase in TLR9 activation over unmodified SEQ ID NO:1 and unmodified B class ODN SEQ ID NO:37 (FIG. 6).

TABLE 2 Examples of modified oligonueleotides with lipophilie base analog substitutions Seq ID description/ No# Oligonucleotide sequence class derived from  1 T*G*T*C-G*T*T*T*T*T*T*T*T*T*T*T*T*T*T*T Unmodified 41 T*G*CU*C-G*T*T*T*T*T*T*T*T*T*T*T*T*T*T*T CI derivative of SEQ ID NO: 1 10 T*G*BU*C-G*T*T*T*T*T*T*T*T*T*T*T*T*T*T*T 5′BU derivative of SEQ ID NO: 1 13 T*G*JU*C-G*T*T*T*T*T*T*T*T*T*T*T*T*T*T*T 5′JU derivative of SEQ ID NO: 1 16 T*G*U*C-G*T*T*T*T*T*T*T*T*T*T*T*T*T*T*T U derivative of SEQ ID NO: 1 41 T*G*CU*C-G*T*T*T*T*T*T*T*T*T*T*T*T*T*T*T CU derivative of SEQ ID NO: 1 42 T*G*EU*C-G*T*T*T*T*T*T*T*T*T*T*T*T*T*T*T EU derivative of SEQ ID NO: 1 29 T*G*T*C-G*EU*T*T*T*T*T*T*T*T*T*T*T*T*T*T 3′ EU derivative of SEQ ID NO: 1 30 T*G*EU*C-G*EU*T*T*T*T*T*T*T*T*T*T*T*T*T*T 5′3′ EU derivative of SEQ ID NO: 1 *phosphorothioate internucleotide linkage -phosphodiester internucleotide linkage

Example 4 Lipophilic Substitution on Oligonucleotides of A, B, C, P, and T Classes

To investigate the effects of lipophilic base analog substitution on the different classes of ODN, modifications were made on A class, B class, C class, P class, and T class oligonucleotides. Some examples of these oligonucleotides are given in Table 3.

TABLE 3 JU-modified oligonucleotides of A B, C, P, and T class Seq ID No. Modified Oligonucleotides Oligo Class 16 T*G*U*C-G*T*T*T*T*T*T*T*T*T*T*T*T*T*T*T B 17 T*G*T*C-G*U*T*T*T*T*T*T*T*T*T*T*T*T*T*T B 18 T*G*U*C-G*U*T*T*T*T*T*T*T*T*T*T*T*T*T*T B 19 JU*C*G*T*C*G*T*T*T*T*T*C*G*G*T*C*G*T*T*T*T B 20 T*C*G*JU*C*G*T*T*T*T*T*C*G*G*T*C*G*T*T*T*T B 21 T*C*G*T*C*G*T*T*T*T*T*C*G*G*JU*C*G*T*T*T*T B 22 JU*C*G*JU*C*G*T*T*T*T*T*C*G*G*T*C*G*T*T*T*T B 23 T*C*G*JU*C*G*JU*T*T*T*T*C*G*G*T*C*G*T*T*T*T B 24 T*C*G*T*C*G*T*T*T*T*T*C*G*G*JU*C*G*JU*T*T*T B 25 T*C*T*T*T*T*T*T*G*T*C-G*T*T*T*T*T*T*T*T*T*T T 26 T*G*C*T*G*C*T*T*T*T*G*T*G*C*T*T*T*T*G*T*G*C*T*T Non CpG ODN 27 JU*C-G*T*C*G*T*T*T*T*A*C*G*G*C*G*C*C*G*T*G*C*C*G C 28 T*C*G*JU*C-G*T*T*T*T*A*C*G*G*C*G*C*C*G*T*G*C*C*G C 31 JU*C-G*T*C*G*A*C*G*A*T*C*G*G*C*G*C*G*C*G*C*C*G P 32 T*C*G*JU*C-G*A*C*G*A*T*C*G*G*C*G*C*G*C*G*C*C*G P 33 JU*C-G*JU*C*G*A*C*G*A*T*C*G*G*C*G*C*G*C*G*C*C*G P 34 JU*C-G-A-C-G-T-C-G-T-G-G*G*G*G A 35 T*C-G-A-C-G-JU-C-G-T-G-G*G*G*G A 36 T*C-G-A-C-G-JU-C-G-JU-G-G*G*G*G A 37 T*C*G*T*C*G*T*T*T*T*T*C*G*G*T*C*G*T*T*T*T B 43 T*C-G-A-C-G-T-C-G-T-G-G*G*G*G A 44 JU*C-G*JU*C*G*T*T*T*T*A*C*G*G*C*G*C*C*G*T*G*C*C*G P 45 T*C*G*JU*C-G*JU*T*T*T*A*C*G*G*C*G*C*C*G*T*G*C*C*G P 46 T*C*G*T*C-G*T*T*T*T*A*C*G*G*C*G*C*C*G*T*G*C*C*G P 47 T*C*T*T*T*T*T*T*G*JU*C-G*T*T*T*T*T*T*T*T*T*T T 48 T*C*T*T*T*T*T*T*JU*C-G*JU*T*T*T*T*T*T*T*T*T T 49 JU*C*T*T*T*T*T*T*G*T*C-G*T*T*T*T*T*T*T*T*T*T T 50 JU*C-T*T*T*T*T*TG*T*C-G*T*T*T*T*T*T*T*T*T*T T 51 T*C*T*T*T*T*T*T*G*U*C-G*T*T*T*T*T*T*T*T*T*T T 52 T*C-G*T*C*G*A*C*G*A*T*C*G*G*C*G*C*G*C*G*C*C*G P -pliosphodiester internuclentide linkage *phosphorothioate internuclectide linkage

To investigate activation of human TLR9 by modified B class oligonucleotides, 5-iodo-2′-deoxyuridine-modified B-class derivatives of SEQ ID NO:3 were evaluated in a luciferase assay for their ability to activate TLR9 (see materials and methods). All modified B-class oligonucleotides showed a significant increase in TLR9 activation over unmodified SEQ ID NO:37 (FIG. 7).

To investigate activation of human TLR9 by modified A-class oligonucleotides, 5-iodo-2′-deoxyuridine-modified A-class derivatives of SEQ ID NO:43 were tested for their ability to activate TLR9 in a luciferase assay (FIG. 8a ) and a PBMC assay (FIG. 8b ) as in FIG. 5. The increase in TLR9 stimulation was pronounced when the modification was 5′ to the CpG motif; although double substitution with 5-iodouracil (JU) 5′ and 3′ of the CpG motif resulted in most potent stimulation.

To investigate the activation of human TLR9 by modified C class oligonucleotides, 5-iodo-2′-deoxyuridine-modified C class derivatives of SEQ ID NO:46, SEQ ID NO:44 and 45, were tested for their ability to activate TLR9. A class sequences SEQ ID NO:43 (unmodified) and SEQ ID NO:35 and 36 were tested simultaneously. As shown in FIG. 9, modified ODN SEQ ID NO:35, 36, 44, and 45 all showed increased stimulation of TLR9 above unmodified A and C class in a luciferase assay. To investigate the activation of human TLR9 by modified P class oligonucleotides, 5-iodo-2′-deoxyuridine-modified P class derivatives of SEQ ID NO:46 were tested for their ability to activate TLR9 in a luciferase assay. As shown in FIG. 10, modified ODN SEQ ID NO:31-33 showed a increased stimulation of TLR9 over unmodified ODN.

To investigate the activation of human TLR9 by modified T class oligonucleotides, 5-iodo-2′-deoxyuridine-modified T class derivatives of unmodified T class ODN SEQ ID NO:52 were tested for their ability to activate TLR9. As shown in FIG. 11, modified ODN SEQ ID NOs 47-50 showed an increased stimulation of TLR9 over unmodified T class ODN in a luciferase assay. The uridine derivative SEQ ID NO:51 showed reduced stimulation of TLR9.

As the above examples demonstrate, substitution of lipophilic T-analogs 5′ to the CpG motif results in a strong increase in TLR9 activation in all classes tested, and resulted in an increased ability to induce IFN-alpha production.

Example 5 Stimulation of TLR9 by Short Modified Oligonucleotides

As the modified CpG ODN of 20 nucleotides in length showed an unusual affinity for TLR9 activation, very short CpG ODN were investigated for their ability to activate TLR9. Very short oligonucleotides would be a great advantage over longer oligonucleotides for use in treatment because of the increased ease in uptake by cells, as well as the potential a simpler formulation, without the use of DOTAP. Three short CpG ODN (shortmers) were investigated (Table 3): a 6-mer CpG motif hexamer (SEQ ID NO:38), a 5′JU modification of the hexamer (SEQ ID NO:39), and a 5′3′ JU modification of the hexamer (SEQ ID NO:40) (Table 4). The activity of the shortmers was compared to the unmodified B class oligonucleotide SEQ ID NO:37 in a luciferase assay. As shown in FIG. 12, most particularly with SEQ ID NO:40, the use of modified shortmers shows great potential as an improved immunotherapy medicament.

TABLE 4 Modified short oligonucleotides SEQ ID No. Shortmer sequence Modification 38 G*T*C-G*T*T Unmodified 39 G*JU*C-G*T*T 5′ JU 40 G*JU*C-G*JU*T 5′ and 3′ JU 37 T*C*G*T*C*G*T*T*T*T*T*C*G*G*T*C*G*T*T*T*T Unmodified B class *phosphorothioate internucleolide linkage -phosphodiester internucleofide linkage

Example 6 Activation of TLR9 Pathway In Vivo by Modified Oligonucleotide

In order to determine the efficacy of the modified ODN of the invention in vivo, ODN with lipophilic T analogs were tested in isolated mouse splenocytes. BALB/c mouse splenocytes were isolated and incubated with modified B class (SEQ ID NO:13), unmodified B class (SEQ ID NO:37), and a non-CpG ODN (SEQ ID NO:26) (Table 5). Culture supernatants were collected at 6 hour (TNF-alpha) or 24 hours (IL-6, IL-10, IL-12) and cytokine concentration was measured by ELISA. As shown in FIG. 13, incubation with modified SEQ ID NO:13 resulted in dramatically increased levels of all cytokines tested.

ODN were then tested their ability to induce B cell proliferation in splenocytes. CFSE-stained BALB/c mouse splenocytes (4×10⁵/well) were incubated with 0.001, 0.01, 0.1, 0.3, 1, 3 or 10 μg/ml of the indicated ODN (FIG. 14). At 72 hours post-incubation, cells were stained for cell surface marker CD19 and B-cell proliferation was determined by FACS followed by analysis by ModFit Software. As shown in FIG. 14, incubation with modified SEQ ID NO:13 resulted in a marked increase in B-cell proliferation. The increase was most pronounced even at lower ODN concentration.

To measure the effect of modified ODN in vivo, BALB/c mice (5 per group) were injected subcutaneously (SC) with 10, 50 or 100 μg of SEQ ID NO:13 or 100 μg of SEQ ID NO:37 in a total volume of 100 μl SC. Control group received 100 μl of PBS alone. Animals were bled by cardiac puncture at 1 hour post injection (TNF-alpha) or 3 hours post injection (IP-10). Plasma samples were assayed ELISA for TNF-alpha (FIG. 15a ) and IP-10 (FIG. 15b ). Injection of BALB/c mice with modified SEQ ID NO:13 resulted in higher TNF-alpha and IP-10 production than the non-modified SEQ ID NO:37, demonstrating that the lipophilic base shape substituted ODN of the invention result in greater immune stimulation in vivo than unmodified immune stimulatory ODN.

TABLE 5 Oligonucleotides tested in vivo Seq ID No. Sequence Modification 13 T*G*JU*C-G*T*T*T*T*T*T*T*T*T*T*T*T*T*T*T 5 JU derivative of  SEQ ID NO: 1 37 T*C*G*T*C*G*T*T*T*T*T*C*G*G*T*C*G*T*T*T*T Unmodfified B class 26 T*G*C*T*G*CC*T*T*T*T*G*T*G*C*T*T*T*T*G*T*G*C*T*T Non CpG control *phosphorothioate intemucleotide linkage -phosphodiester intemucleotide linkage

Example 7 Oligonucleotides with Additional Modifications

ODN with lipophilic base analogs were tested for their ability to induce TLR9-mediated NF-κB activity in a luciferase assay (see materials and methods). FIGS. 16-23 show the activity of ODN with additional modifications (see table 6).

In order to test the activity of other base analogs, the activity of 6-nitrobenzimidazol (6NB)-modified ODN SEQ ID NO:178 and unmodified parent sequence SEQ ID NO:1 was compared. As shown in FIG. 12, SEQ ID NO:178 was able to activate TLR9-mediated NF-κB to a degree comparable with the unmodified parent sequence. Next the activity of 5-(2-bromovinyl)-uridine modified ODN (SEQ ID NO:153-154) was compared to that of unmodified parent sequence SEQ ID NO:1. As shown in FIG. 17, both modified ODN were more active in the assay than the parent sequence. Neat the activity of two B-class ODN with 5-proynyl-dU (SEQ ID NO:116 and 117) in place of thymidine of the parent sequence (SEQ ID NO:1). As shown in FIG. 21, both modified ODN had activity comparable to that of the parent sequence. The activity of SEQ ID NO:116, in which the modification is 5′ to the CG dinucleotide, was slightly improved over the parent sequence.

In order to test the effect of a second type of modification on JU-modified ODN, 2′O-methylguanosines were incorporated into JU-modified ODN. The activity of 2′-O-methylguanosine/JU ODN SEQ ID NO:111-113 was compared to that of parent SEQ ID NO:1 and JU only modified SEQ ID NO:13. As shown in FIG. 18, all JU-modified ODN were more active than the parent ODN. ODN with the 2′O-methylguanosine modification 3′ of the CG dinucleotide (SEQ ID NO:112-113) were slightly more active than the ODN with the 2′O-methylguanosine modification 5′ of the CG dinucleotide (SEQ ID NO:111) or the ODN modified with JU alone (SEQ ID NO:13).

Next the activity of the JU-modified branched ODN (SEQ ID NO:96, 97, 101, and 102) was compared to that of SEQ ID NO:1. As shown in FIG. 19, the branched ODN with two accessible 5′ ends were all as active or more active than the unmodified SEQ ID NO:1 in the assay. SEQ ID NO:101 and 102, with the triethyleneglycol phosphate spacer, were more active than SEQ ID NO:96 AND 97 with the 3′-O-Methyl-G spacer.

Next the activity of a short unmodified B-class ODN (SEQ ID NO:38) and an ODN of the same sequence with a lipophilic substituted nucleotide analog and a lipophilic 3′ tag (SEQ ID NO:126) was compared. Both were formulated with and without DOTAP. As shown in FIG. 20, the addition of the JU-modification and the lipophilic tag greatly enhanced the activity of the ODN, as did the addition of DOTAP.

Next the activity of B-class ODN with a second nucleotide analog in addition to a lipophilic substituted nucleotide analog (SEQ ID NO:138, 7-deaza-dG; SEQ ID NO:139, inosine; SEQ ID NO:140, 5-methyl-dC) was compared to that of the parent sequence (SEQ ID NO:1) and the same sequence with a lipophilic substituted nucleotide analog only (SEQ ID NO:13). As shown in FIG. 22, all modified ODN were more active in the assay than the parent ODN

Next the activity of T-class ODN with a lipophilic substituted nucleotide analog (SEQ ID NO:132-134) was compared to that of a C-class ODN (SEQ ID NO:198) known to be immunostimulatory. As shown in FIG. 23, all modified ODN showed much greater activity in the assay than the unmidified C-class ODN.

TABLE 6 Lipophilic substituted oligonuclotides with additional modifications Seq ID No. Sequence Type and modfication   1 T*G*T*C-G*T*T*T*T*T*T*T*T*T*T*T*T*T*T*T unmodified B-class  13 T*G*JU*C-G*T*T*T*T*T*T*T*T*T*T*T*T*T*T*T B-class: 5′JU derivative of SEQ ID NO: 1  38 G*T*C-G*T*T Unmodified B-class  96 (T*G*JU*C-G*T*T*L*)2doub-3mg 3′3′-branched  97 (JU*C*G*T*T*C*G*L*)2doub-3mg 3′3′-branched 101 (T*G*JU*C-G*T*T*L*)2doub-teg 3′3′-branched 102 (JU*C*G*T*T*C*G*L*)2doub-teg 3′3′-branched 111 T*mG*JU*C-G*T*T*T*T*T*T*T*T*T*T*T*T*T*T*T 2′-O-methyl-modified B-class 112 T*G*JU*C-mG*T*T*T*T*T*T*T*T*T*T*T*T*T*T*T 2′-O-methyl-modified B-class 113 T*mG*JU*C-mG*T*T*T*T*T*T*T*T*T*T*T*T*T*T*T 2′-O-methyl-modified B-class 116 T*G*PU*C-G*T*T*T*T*T*T*T*T*T*T*T*T*T*T*T B-class with 5-proynyl-dU (PU) 117 T*G*T*C-G*PU*T*T*T*T*T*T*T*T*T*T*T*T*T*T B-class with 5-proynyl-dU (PU) 126 G*JU*C-G*JU*T-hex B-class derivative of 38 with JU and hexadaclglyceryl 3′ tag 132 JU*C*T*T*T*T*T*T*T*T*C*G*T*T*T*T*T*T*T*T*T*T T-class 133 T*C*T*T*T*T*T*T*T*JU*C*G*T*T*T*T*T*T*T*T*T*T T-class 134 JU*C*T*T*T*T*T*T*T*JU*C*G*T*T*T*T*T*T*T*T*T*T T-class 138 T*G*JU*C-E*T*T*T*T*T*T*T*T*T*T*T*T*T*T*T B-class with 7-deaza-dG (E) 139 T*G*JU*C-I*T*T*T*T*T*T*T*T*T*T*T*T*T*T*T B-class with inosine (I) 140 T*G*JU*Z-G*T*T*T*T*T*T*T*T*T*T*T*T*T*T*T B-class with 5-metyl-dC (Z) 153 T*G*BVU*C-G*T*T*T*T*T*T*T*T*T*T*T*T*T*T*T B-class with 5-(2-bromo-vinyl)- uridine (BVU) 154 T*G*T*C-G*BVU*T*T*T*T*T*T*T*T*T*T*T*T*T*T B-class with 5-(2-bromo-vinyl)- uridine (BVU) 178 T*G*BNB*C-G*T*T*T*T*T*T*T*T*T*T*T*T*T*T*T B-class with 6-nitro- benzimidazol (6NB) 198 C*G*G*C*G*C*C*T*C*G C-class *phosphorothloate internueleotide linkage -phosphodiester internueleotide linkage

Example 8 Activity of Modified P-Class Oligonucleotides

P-class ODN with lipophilic base analogs were tested for the ability to activate the NF-kB pathway through TLR9 as measured by luciferase assay. The activity of P-class ODN with a lipophilic substituted nucleotide analog (SEQ ID NO:58-61) was compared to that of a B-class positive control (SEQ ID NO:55) and an unmodified P-class ODN (SEQ ID NO:56). As shown in FIG. 24, all modified P-class ODN showed increased TLR9 stimulation compared to the controls. FIG. 24a shows JU-modified P-class ODN and 24 b shows EU-modified P-class ODN.

Next the activity of modified P-class ODN (SEQ ID NO:64 (EU-modified), 66-67 (JU-modified) was compared to that of a B-class positive control (SEQ ID NO:55), a C-class ODN (SEQ ID NO:68) and an unmodified P-class ODN (SEQ ID NO:57). As shown in FIG. 25, all modified ODN showed a higher degree of TLR9 stimulation than the unmodified P class ODN. SEQ ID NO:66, with the phosphodiester bond in the CG dinucleotide, showed reduced activity compared to the fully phosphorothioate SEQ ID NO:67.

Next the modified P-class ODN were tested for their ability to induce expression of IFN-alpha. The activity of P-class ODN with a lipophilic substituted nucleotide analog (SEQ ID NO:58-61) was compared to that of a B-class positive control (SEQ ID NO:55) and an unmodified P-class ODN (SEQ ID NO:56) as measured by an ELISA assay. As shown in FIG. 26, all modified P-class ODN showed an increase in IFN-alpha induction. FIG. 26a shows JU-modified P-class ODN and 26 b shows EU-modified P-class ODN.

Next the modified P-class ODN (EU-modified), 66-67 (JU-modified) was compared to that of a B-class positive control (SEQ ID NO:55), a C-class ODN (SEQ ID NO:68) and an unmodified P-class ODN (SEQ ID NO:57) for the ability to induce IFN-alpha as measured by an ELISA assay. As shown in FIG. 27, the modified P-class ODN showed enhanced ability to induce IFN-alpha. As in FIG. 24, SEQ ID NO:66 showed reduced activity compared to SEQ ID NO:67.

Next the modified P-class ODN were tested for the ability to induce IL-6 in human PBMC. PBMC from three donors were incubated with ODN at concentrations as indicated for 24 h, followed by luminex 25-plex analysis of the supernatants for IL-6. The activity of modified P-class ODN (SEQ ID NO:58, 60-62, FIG. 28a ) (SEQ ID NO:64 and 67, FIG. 28b ) was compared to that of an unmodified B-class ODN (SEQ ID NO:55), and unmodified C-class ODN (SEQ ID NO:54), a negative control ODN (SEQ ID NO:53), and an unmodified P-class ODN (SEQ ID NO:56). The JU-modified ODN (SEQ ID NO:58, 60-61 and 67) showed a slightly higher activation of IL-6 than did the EU-modified ODN (SEQ ID NO:62 and 64). All modified ODN showed increased activity compared to unmodified ODN.

Next the activity of modified P-class class ODN (SEQ ID NO 58, 60-62, FIG. 29a ) (SEQ ID NO:64 and 67, FIG. 29b ) was compared to that of an unmodified B-class ODN (SEQ ID NO:55), an unmodified C-class ODN (SEQ ID NO:54), a negative control ODN (SEQ ID NO:53), an unmodified P-class ODN (SEQ ID NO:56) LPS, R-848, SEB, and a poly[I]:[C] ODN. CFSE-labeled PBMC from three donors were incubated with the ODN for 5 days and then stained with a CD19 antibody. The percentage of B cells with reduced CFSE staining was determined. Treatment with the B-class ODN resulted in the highest percentage of B cells after division. Treatment with the JU-modified ODN resulted in a higher percentage of B cells than the EU-modified ODN.

In order to determine the effect of the modified P-class ODN in vivo, BALB/c mice (5 per group) were injected SC with differing doses of ODN. Animals were bled at 3 hr post injection and plasma tested for IFN-alpha by ELISA. The activity of modified P-class ODN(SEQ ID NO:58, 60-62, 64, and 67) was compared to that of a B-class negative control (SEQ ID NO:55) and a negative control (SEQ ID NO:26). As shown in FIG. 30, treatment with the JU-modified ODN SEQ NO:58, 60, and 61 resulted in slightly higher IFN-alpha induction than the EU-modified ODN SEQ ID NO:64. The B-class ODN SEQ ID NO:55 did not induce much murine IFN-alpha, as expected.

Next the modified P-class ODN were evaluated for their ability to reduce tumor volume mouse SA1N tumor model. Female A/J mice (10 per group) were injected SC with 5×10⁵ SaI/N tumor cells an day 0. Mice were treated with 35 g (FIG. 31a ) or 100 μg (FIG. 31b ) P-class ODN with a lipophilic substituted nucleotide analog (SEQ ID NO:60, 64, and 67), an unmodified C-class ODN, an unmodified B-class ODN (SEQ ID NO:55), or PBS alone. ODN were given SC once weekly starting on day 8 post tumor induction. Animals were monitored for survival and tumor volume. As shown in FIG. 31a , at the lower dosage treatment with the modified P-class ODN showed the greatest reduction in tumor volume, suggesting that these ODN would be effective in treating cancer. At the higher dosage in 31 b, all modified P-class ODN and the C-class ODN were effective in reducing tumor volume.

TABLE 7 Modified P-class oligonucleotides Seq ID Type and No. Sequence modification 53 T*C*C*A*G*G*A*C*T*T*C*T*C*T*C*A*G*G*T*T neg control 54 T*C*G*T*C*G*T*T*T*T*C*G*G*C*G*C*G*C*G*C*C*G C-class 55 T*C*G*T*C*G*T*T*T*T*G*T*C*G*T*T*T*T*G*T*C*G*T*T B-class 56 T*C-G*A*C*G*T*C*G*A*T*C*G*G*C*G*C*G*C*G*C*C*G P-class T->A, 5′ CpG PO 57 T*C-G*T*C*G*A*C*G*A*T*C*G*G*C*G*G*C*C*G*C*C*G P-class 3′ palin- drome, 5′ CpG PO 58 JU*C-G*A*C*G*T*C*G*A*T*C*G*G*C*G*C*G*C*G*C*C*G P-class 59 JU*C*G*A*C*G*T*C*G*A*T*C*G*G*C*G*C*G*C*G*C*C*G P-class 60 JU*C-G*A*C*G*T*C*G*A*T*C*G*G*C*G*C*G*C*G*C*C*G*T P-class 61 JU*C*G*A*C*G*T*C*G*A*T*C*G*G*C*G*C*G*C*G*C*C*G*T P-class 62 EU*C-G*A*C*G*T*C*G*A*T*C*G*G*C*G*C*G*C*G*C*C*G P-class 63 EU*C-G*A*C*G*T*C*G*A*T*C*G*G*C*G*C*G*C*G*C*C*G P-class 64 EU*C-G*A*C*G*T*C*G*A*T*C*G*G*C*G*C*G*C*G*C*C*G P-class 65 EU*C*G*A*C*G*T*C*G*A*T*C*G*G*C*G*C*G*C*G*C*C*G P-class 66 JU*C-G*T*C*G*A*C*G*A*T*C*G*G*C*G*G*C*C*G*C*C*G*T P-class 67 JU*C*G*T*C*G*A*C*G*A*T*C*G*G*C*G*G*C*C*G*C*C*G*T P-class 68 T*C_G*C_G*T*C_G*T*T*C_G*G*C*G*C_G*C*G*C*C*G C-class *phosphorothloate internueleotide linkage -phosphodiester internueleotide linkage

A summary of Exemplary modified ODN is presented in Table 8:

TABLE 8 Seq ID No# Oligonucleotide sequence   3 T*G*FF*C-G*T*T*T*T*T*T*T*T*T*T*T*T*T*T*T   4 T*G*T*C-G*FF*T*T*T*T*T*T*T*T*T*T*T*T*T*T   5 T*G*FF*C-G*FF*T*T*T*T*T*T*T*T*T*T*T*T*T*T   6 T*G*T*FF-G*T*T*T*T*T*T*T*T*T*T*T*T*T*T*T   7 T*G*T*C-FF*T*T*T*T*T*T*T*T*T*T*T*T*T*T*T   8 T*FF*C-G*T*T*T*T*T*T*T*T*T*T*T*T*T*T*T*T   9 T*G*T*C-G*T*FF*T*T*T*T*T*T*T*T*T*T*T*T*T  10 T*G*BU*C-G*T*T*T*T*T*T*T*T*T*T*T*T*T*T*T  11 T*G*T*C-G*BU*T*T*T*T*T*T*T*T*T*T*T*T*T*T  12 T*G*BU*C-G*BU*T*T*T*T*T*T*T*T*T*T*T*T*T*T  13 T*G*JU*C-G*T*T*T*T*T*T*T*T*T*T*T*T*T*T*T  14 T*G*T*C-G*JU*T*T*T*T*T*T*T*T*T*T*T*T*T*T  15 T*G*JU*C-G*JU*T*T*T*T*T*T*T*T*T*T*T*T*T*T  16 T*G*U*C-G*T*T*T*T*T*T*T*T*T*T*T*T*T*T*T  17 T*G*T*C-G*U*T*T*T*T*T*T*T*T*T*T*T*T*T*T  18 T*G*U*C-G*U*T*T*T*T*T*T*T*T*T*T*T*T*T*T  19 JU*C*G*T*C*G*T**T*T*T*T*C*G*G*T*C*G*T*T*T*T  20 T*C*G*JU*C*G*T*T*T*T*T*C*G*G*T*C*G*T*T*T*T  21 T*C*G*T*C*G*T*T*T*T*T*C*G*G*JU*C*G*T*T*T*T  22 JU*C*G*JU*C*G*T*T*T*T*T*C*G*G*T*C*G*T*T*T*T  23  T*C*G*JU*C*G*JU*T*T*T*T*C*G*G*T*C*G*T*T*T*T  24 T*C*G*T*C*G*T*T*T*T*T*C*G*G*JU*C*G*JU*T*T*T  27 JU*C-G*T*C*G*T*T*T*T*A*C*G*G*C*G*C*C*G*T*G*C*C*G  28 T*C*G*JU*C-G*T*T*T*T*A*C*G*G*C*G*C*C*G*T*G*C*C*G  29 T*G*T*C-G*EU*T*T*T*T*T*T*T*T*T*T*T*T*T*T  30 T*G*EU*C-G*EU*T*T*T*T*T*T*T*T*T*T*T*T*T*T  31 JU*C-G*T*C*G*A*C*G*A*T*C*G*G*C*G*C*G*C*G*C*C*G  32 T*C*G*JU*C-G*A*C*G*A*T*C*G*G*C*G*C*G*C*G*C*C*G  33 JU*C-G*JU*C*G*A*C*G*A*T*C*G*G*C*G*C*G*C*G*C*C*G  34 JU*C-G-A-C-G-T-C-G-T-G-G*G*G*G  35 T*C-G-A-C-G-JU-C-G-T-G-G*G*G*G  36 T*C-G-A-C-G-JU-C-G-JU-G-G*G*G*G  39 G*JU*C-G*T*T  40 G*JU*C-G*JU*T  41 T*G*CU*C-G*T*T*T*T*T*T*T*T*T*T*T*T*T*T*T  42 T*G*EU*C-G*T*T*T*T*T*T*T*T*T*T*T*T*T*T*T  44 JU*C-G*JU*C*G*T*T*T*T*A*C*G*G*C*G*C*C*G*T*G*C*C*G  45 T*C-G*JU*C*G*JU*T*T*T*A*C*G*G*C*G*C*C*G*T*G*C*C*G  47 T*C*T*T*T*T*T*T*G*JU*C-G*T*T*T*T*T*T*T*T*T*T  48 T*C*T*T*T*T*T*T*G*JU*C-G*JU*T*T*T*T*T*T*T*T*T  49 JU*C*T*T*T*T*T*T*G*T*C-G*JU*T*T*T*T*T*T*T*T*T*T  50 JU*C-T*T*T*T*T*T*G*T*C-G*T*T*T*T*T*T*T*T*T*T  51 T*C*T*T*T*T*T*T*G*U*C-G*T*T*T*T*T*T*T*T*T*T  58 JU*C-G*A*C*G*T*C*G*A*T*C*G*G*C*G*C*G*C*G*C*C*G  59 JU*C*G*A*C*G*T*C*G*A*T*C*G*G*C*G*C*G*C*G*C*C*G  60 JU*C-G*A*C*G*T*C*G*A*T*C*G*G*C*G*C*G*C*G*C*C*G*T  61 JU*C*G*A*C*G*T*C*G*A*T*C*G*G*C*G*C*G*C*G*C*C*G*T  62 EU*C-G*A*C*G*T*C*G*A*T*C*G*G*C*G*C*G*C*G*C*C*G  63 EU*C*G*A*C*G*T*C*G*A*T*C*G*G*C*G*C*G*C*G*C*C*G  64 JU*C-G*T*C*G*A*C*G*A*T*C*G*G*C*G*G*C*C*G*C*C*G*T  65 JU*C*G*T*C*G*A*C*G*A*T*C*G*G*C*G*G*C*C*G*C*C*G*T  66 EU*C-G*T*C*G*A*C*G*A*T*C*G*G*C*G*G*C*C*G*C*C*G  67 JU*C-G*T*C*G*A*C*G*A*T*C*G*G*C*G*G*C*C*G*C*C*G  78 T*G*T*C-G*FU*T*T*T*T*T*T*T*T*T*T*T*T*T*T  79 T*G*FU*C-G*FU*T*T*T*T*T*T*T*T*T*T*T*T*T*T  80 T*G*Y*C-G*U*T*T*T*T*T*T*T*T*T*T*T*T*T*T  81 T*G*T*C-6NB*T*T*T*T*T*T*T*T*T*T*T*T*T*T*T  82 T*G*T*6NB-G*T*T*T*T*T*T*T*T*T*T*T*T*T*T*T  83 T*G*T*6NB-G-T*T*T*T*T*T*T*T*T*T*T*T*T*T*T  84 JU*G*T*C-G*T*T*T*T*T*T*T*T*T*T*T*T*T*T*T  85 JU*G*JU*C-G*T*T*T*T*T*T*T*T*T*T*T*T*T*T*T  86 T*G*T*C-G*T*JU*T*T*T*T*T*T*T*T*T*T*T*T*T  87 T*G*FT*C-G*T*T*T*T*T*T*T*T*T*T*T*T*T*T*T  88 T*G*T*C-G*FT*T*T*T*T*T*T*T*T*T*T*T*T*T*T  89 T*G*FT*C-G*FT*T*T*T*T*T*T*T*T*T*T*T*T*T*T  90 T*G*CU*C-G*T*T*T*T*T*T*T*T*T*T*T*T*T*T*T  91 T*G*T*C-G*CU*T*T*T*T*T*T*T*T*T*T*T*T*T*T  92 T*G*CU*C-G*CU*T*T*T*T*T*T*T*T*T*T*T*T*T*T  93 T*JU*C-G*T*T*T*T*T*T*T*T*T*T*T*T*T*T*T*T  94 T*G*JU*C-G*T*T*T*T  95 T*G*JU*C-G*T*T*T*T*G*T*C-G*T*T  96 (T*G*JU*C-G*T*T*L*)2doub-3mG  97 (JU*C*G*T*T*C*G*L*)2doub-3mG  98 T*T*JU*C-G*T*C-G*T*T*T*C-G*T*C-G*T*T  99 BU*C-G-A-C-G-T-C-G-T-G-G-G*G*G 100 T*G*JU*G-C*T*T*T*T*T*T*T*T*T*T*T*T*T*T*T 101 (T*G*JU*C-G*T*T*L*) 102 (JU*C*G*T*T*C*G*L*)2doub-teg 103 JU*C-G*T*C*G*T*T*T*T*C*G*G*C*G*C*G*C*G*C*C*G 104 T*C*G*JU*C-G*T*T*T*T*C*G*G*C*G*C*G*C*G*C*C*G 105 T*C*G*T*C*G*T*T*T*JU*C-G*G*C*G*C*G*C*G*C*C*G 106 JU*C*G*T*C*G*T*T*T*T*T*T*C*G*G*JU*C*G*T*T*T*T 107 T*C*G*JU*C*G*T*T*T*T*T*C*G*G*JU*C*G*T*T*T*T 108 T*G*JU*C-G*T*T*T*T*T*T*T*T*T*G*JU*C-G*T*T 109 T*G*JU*C*G*T*T*T*T*T*T*T*T*T*T*T*T*T*T*T 110 JU*C-G-A-C-G-T-C-G-T-G-G*E*G*G 111 T*mG*JU*C-G*T*T*T*T*T*T*T*T*T*T*T*T*T*T*T 112 T*G*JU*C-mG*T*T*T*T*T*T*T*T*T*T*T*T*T*T*T 113 T*mG*JU*C-mG*T*T*T*T*T*T*T*T*T*T*T*T*T*T*T 114 JU*C-G*JU*C*G*T*T*T*T*T*C*G*G*T*C*G*T*T*T*T 115 JU*C*G*JU*C-G*T*T*T*T*T*C*G*G*T*C*G*T*T*T*T 116 T*G*PU*C-G*T*T*T*T*T*T*T*T*T*T*T*T*T*T*T 117 T*G*T*C-G*PU*T*T*T*T*T*T*T*T*T*T*T*T*T*T 118 BU*C-G-A-C-G-T-C-G-T-G-G*G*G*G 119 T*G*JU*C-G*T*T*T*T*C*G*G*C*G*C*G*C*G*C*C*G 120 T*JU*C-G*T*T*T*T*C*G*G*C*G*C*G*C*G*C*C*G*T 121 T*EU*C-G*T*T*T*T*T*T*T*T*T*T*T*T*T*T*T 122 T*G*EU*G-C*T*T*T*T*T*T*T*T*T*T*T*T*T*T*T 123 JU*C-G*T*C*G*T*T*T*T*T*C*G*G*T*C*G*T*T*T*T 124 EU*C-G*T*C*G*T*T*T*T*T*C*G*G*T*C*G*T*T*T*T 125 G*JU*C-G*T*T*-hex 126 G*JU*C-G*JU*T-hex 127 G*EU*C-G*EU*T-hex 128 EU*C-G*T*C*G*T*T*T*T*A*C*G*G*C*G*C*C*G*T*G*C*C*G 129 T*C*G*EU*C-G*T*T*T*T*A*C*G*G*C*G*C*C*G*T*G*C*C*G 130 EU*C-G*T*C*G*A*C*G*A*T*C*G*G*C*G*C*G*C*G*C*C*G 131 JU*C*T*T*T*T*T*T*T*T*T*T*T*T*T*T*T 132 JU*C*T*T*T*T*T*T*T*T*C*G*T*T*T*T*T*T*T*T*T*T 133 T*C*T*T*T*T*T*T*T*JU*C*G*T*T*T*T*T*T*T*T*T*T 134 JU*C*T*T*T*T*T*T*T*JU*C*G*T*T*T*T*T*T*T*T*T*T 135 JU*C-G*T*C*G*T*T*T*C*G*T*C*G*T*T*T*T*G*T*C*G*T*T* 136 T*C*G*T*C*G*T*T*T*C*G*T*C*G*T*T*T*T*G*JU*C-G*T*T 137 JU*C-G*T*C*G*T*T*T*C*G*T*C*G*T*T*T*T*G*JU*C-G*T*T 138 T*G*JU*C-E*T*T*T*T*T*T*T*T*T*T*T*T*T*T*T 139 T*G*JU*C-I*T*T*T*T*T*T*T*T*T*T*T*T*T*T*T 140 T*G*JU*C-Z*T*T*T*T*T*T*T*T*T*T*T*T*T*T*T 141 T*G*T*C-G*T*T*JU*T*T*T*T*T*T*T*T*T*T*T*T 142 T*G*T*C-G*T*T*T*JU*T*T*T*T*T*T*T*T*T*T*T 143 JU*C-G*T*C*G*T*T*T*T*C*G*G*C*G*C*G*C*G*C*C*G*T 144 EU*C-G*T*C*G*T*T*T*T*C*G*G*C*G*C*G*C*G*C*C*G*T 145 T*C-G*EU*C*G*T*T*T*T*C*G*G*C*G*C*G*C*G*C*C*G*T 146 T*C-G*T*C*G*T*T*T*JU*C*G*G*C*G*C*G*C*G*C*C*G*T 147 T*C-G*T*C*G*T*T*T*EU*C*G*G*C*G*C*G*C*G*C*C*G*T 148 EU*C-G*T*C*G*T*T*T*EU*C*G*G*C*G*C*G*C*G*C*C*G*T 149 EU*C-G*EU*C*G*T*T*T*T*C*G*G*C*G*C*G*C*G*C*C*G*T 150 JU*C-G*EU*C*G*T*T*T*T*C*G*G*C*G*C*G*C*G*C*C*G*T 151 JU*C-G*T*C*G*T*T*T*T*G*T*C*G*T*T*T*T*G*T*C*G*T*T 152 EU*C-G*T*C*G*T*T*T*T*G*T*C*G*T*T*T*T*G*T*C*G*T*T 153 T*G*BVU*C-G*T*T*T*T*T*T*T*T*T*T*T*T*T*T*T 154 T*G*T*C-G*BVU*T*T*T*T*T*T*T*T*T*T*T*T*T*T 155 JU*C*G*G*C*G*G*C*C*G*C*C*G 156 JU*C*G*T*C*G*T*T*T*T*A*C*G*G*C*G*C*C*G*T*G*C*C*3mG 157 EU*C*G*T*C*G*T*T*T*T*A*C*G*G*C*G*C*C*G*T*G*C*C*3mG 158 EU*C*G*EU*C*G*T*T*T*T*A*C*G*G*C*G*C*C*G*T*G*C*C*3mG 159 EU*C-G*EU*C*G*T*T*T*T*A*C*G*G*C*G*C*C*G*T*G*C*C*3mG 160 EU*C*G*T*C*G*T*T*T*T*A*C*G*G*C*G*C*C*G*T*G*C*C*G*iT 161 JU*C*G*T*C*G*T*T*T*T*C*G*G*C*G*C*G*C*G*C*C*3mG 162 EU*C*G*T*C*G*T*T*T*T*C*G*G*C*G*C*G*C*G*C*C*3mG 163 EU*C-G*T*C*G*T*T*T*T*C*G*G*C*G*C*G*C*G*C*C*3mG 164 EU*C*G*EU*C*G*T*T*T*T*C*G*G*C*G*C*G*C*G*C*C*3mG 165 EU*C-G*EU*C*G*T*T*T*T*C*G*G*C*G*C*G*C*G*C*C*3mG 166 EU*C*G*T*C*G*T*T*T*EU*C*G*G*C*G*C*G*C*G*C*C*3mG 167 JU*C*G*T*C*G*T*T*T*JU*C*G*G*C*G*C*G*C*G*C*C*3mG 168 EU*C*G*T*C*G*T*T*T*T*C*G*G*C*G*C*G*C*G*C*C*G*iT 169 JU*C*G*T*C*G*T*T*T*T*C*G*G*C*G*C*G*C*G*C*C*G*iT 170 EU*C*G*T*C*G*A*C*G*T*T*C*G*G*C*G*C*C*G*T*G*C*C*3mG 171 JU*C*G*T*C*G*A*C*G*T*T*C*G*G*C*G*C*C*G*T*G*C*C*3mG 172 JU*C*G*T*C*G*A*C*G*A*T*C*G*G*C*G*C*G*C*G*C*C*3mG 173 EU*C*G*T*C*G*A*C*G*A*T*C*G*G*C*G*C*G*C*G*C*C*3mG 174 EU*C*G*T*C*G*A*C*G*T*T*C*G*G*C*G*C*C*G*T*G*C*C*G*iT 175 EU*C*G*T*C*G*A*C*G*A*T*C*G*G*C*G*C*G*C*G*C*C*G*iT 176 T*G*bi*C-G*T*T*T*T*T*T*T*T*T*T*T*T*T*T*T 177 T*G*NP*C-G*T*T*T*T*T*T*T*T*T*T*T*T*T*T*T 178 T*G*6NB*C-G*T*T*T*T*T*T*T*T*T*T*T*T*T*T*T 179 EU*C*G*T*C*G*T*T*T*T*T*C*G*G*T*C*G*T*T*T*T 180 JU*C*G*T*C*G*A*C*G*A*T*G*G*C*G*G*C*G*C*C*G*C*C 181 EU*C*G*T*C*G*A*C*G*A*T*G*G*C*G*G*C*G*C*C*G*C*C 182 T*T*C-G*T*T*T*T*C*G*G*C*G*C*G*C*G*C*C*G*T 183 T*EU*C-G*T*T*T*T*C*G*G*C*G*C*G*C*G*C*C*G*T 184 JU*C-G*T*T*T*T*C*G*G*C*G*C*G*C*G*C*C*G*T 185 JU*JU*C-G*T*T*T*T*C*G*G*C*G*C*G*C*G*C*C*G*T 186 T*JU*C*G*T*T*T*T*C*G*G*C*G*C*G*C*G*C*C*G*T 187 EU*C*G*T*C*G*T*T*T*T*A*C*G*G*C*G*C*C*G*T*G*C*C*G*T 188 T*EU*C*G*T*T*T*T*A*C*G*G*C*G*C*C*G*T*G*C*C*G*T 189 T*JU*C*G*T*T*T*T*A*C*G*G*C*G*C*C*G*T*G*C*C*G*T 190 JU*C*G*T*C*G*T*T*T*T*rG*rU*rU*rG*rG*rU 191 EU*C-G*T*C*G*A*C*G*A*T*C*G*G*C*G*G*C*C*G*C*C*G*T 192 EU*C*G*T*C*G*A*C*G*A*T*C*G*G*C*G*G*C*C*G*C*C*G*T 193 EU-C-G*A*C*G*T*C*G*A*T*C*G*G*C*G*C*G*C*G*C*C*G 194 EU-C*G*A*C*G*T*C*G*A*T*C*G*G*C*G*C*G*C*G*C*C*G 195 T*G*U*C-G*T*T*T*T*T*T*T*T*T*T*T*T*T*T*T 196 T*G*T*C-G*U*T*T*T*T*T*T*T*T*T*T*T*T*T*T

EQUIVALENTS

The foregoing written specification is considered to be sufficient to enable one skilled in the art to practice the invention. The present invention is not to be limited in scope by examples provided, since the examples are intended as a single illustration of one aspect of the invention and other functionally equivalent embodiments are within the scope of the invention. Various modifications of the invention in addition to those shown and described herein will become apparent to those skilled in the art from the foregoing description and fall within the scope of the appended claims. The advantages and objects of the invention are not necessarily encompassed by each embodiment of the invention. 

We claim: 1.-94. (canceled)
 95. An oligonucleotide comprising: the sequence R₁CGR₂, wherein R₁ and R₂ are selected from the group consisting of a lipophilic substituted nucleotide analog (L), a nucleotide, and a linkage; wherein at least one of R₁ and R₂ is a lipophilic substituted nucleotide analog (L), wherein L is selected from 5-chloro-uracil, 5-bromo-uracil, 5-iodo-uracil, 5-ethyl-uracil, and (E)-5-(2-bromovinyl)-uracil, with the proviso that the oligonucleotide is not d[GCGAA(BrU)(BrU)CGC] where BrU is 5-bromo-uracil; wherein at least two nucleotides of the oligonucleotide have a stabilized linkage; and wherein the stabilized linkage is a phosphorothioate, a phosphorodithioate, a methylphosphonate, a methylphosphonothioate, a boranophosphonate, a phosphoramidate, or a dephospho linkage, either as an enantiomeric mixture or as an enantiomeric pure S- or R-configuration.
 96. The oligonucleotide of claim 95, wherein R₁ and R₂ are both L.
 97. The oligonucleotide of claim 95, wherein R₁ is L and R₂ is a nucleotide.
 98. An oligonucleotide comprising: the sequence R₁CGR₂, wherein R₁ and R₂ are selected from the group consisting of a lipophilic substituted nucleotide analog (L), a nucleotide, and a linkage; wherein at least one of R₁ and R₂ is a lipophilic substituted nucleotide analog (L), wherein L is selected from 5-chloro-uracil, 5-bromo-uracil, 5-iodo-uracil, 5-ethyl-uracil, and (E)-5-(2-bromovinyl)-uracil; and wherein R₁ is a L and R₂ is a linkage, such that the oligonucleotide comprises a structure 5′LCG3′, wherein L is the 5′ terminal nucleotide.
 99. The oligonucleotide of claim 95, wherein R₁ is L and R₂ is a linkage, and wherein R₃ is 5′ to R₁CG, such that the oligonucleotide comprises a structure 5′ R₃R₁CG 3′ and wherein R₃ is a lipophilic group (L) selected from 5-chloro-uracil, 5-bromo-uracil, 5-iodo-uracil, 5-ethyl-uracil, and (E)-5-(2-bromovinyl)-uracil.
 100. The oligonucleotide of claim 95, wherein R₁ is L and R₂ is a linkage, and wherein a second R₁ is 5′ to R₁CG spaced by one nucleotide N, such that the oligonucleotide comprises a structure 5′ R₁NR₁CG 3′.
 101. The oligonucleotide of claim 95, wherein the oligonucleotide is 7-100 nucleotides in length.
 102. The oligonucleotide of claim 95 comprising one to four unmethylated CG dinucleotides.
 103. The oligonucleotide of claim 95 comprising additionally a non-nucleotidic modification, wherein the non-nucleotidic modification is selected from the group consisting of C₆-C₄₈-polyethyleneglycol, C₃-C₂₀-alkane-diol, C₃-C₁₈-alkylamino linker, C₃-C₁₈-alkylthiol linker, cholesterol, bile acid, saturated or unsaturated fatty acid, folate, a hexadecyl-glycerol or dihexadecyl-glycerol group, an octadecyl-glycerol or dioctadecylglycerol group, and a vitamin E group.
 104. The oligonucleotide of claim 95, wherein the stabilized linkage is a phosphorothioate.
 105. The oligonucleotide of claim 95, wherein the CG of R₁CGR₂ has a phosphodiester linkage.
 106. The oligonucleotide of claim 105, wherein all other nucleotides have a phosphorothioate linkage.
 107. An oligonucleotide comprising: the sequence R₁CGR₂, wherein R₁ and R₂ are selected from the group consisting of lipophilic substituted nucleotide analog (L), a nucleotide, and a linkage; wherein at least one of R₁ and R₂ is a liphophilic substituted nucleotide analog (L); wherein L is selected from 5-chloro-uracil, 5-bromo-uracil, 5-iodo-uracil, 5-ethyl-uracil, and (E)-5-(2-bromovinyl)-uracil; wherein the oligonucleotide has the sequence 5′TCN₁TX₁X₂CGX₃X₄ 3′; and wherein X₁ is G or A; X₂ is T, G, or A; X₃ is T or C; and X₄ is T or C; and N₁ is a nucleic acid sequence comprising 0-25 N's, and wherein N is any nucleotide.
 108. A method of treating cancer in a subject comprising administering an oligonucleotide comprising the sequence R₁CGR₂, wherein R₁ and R₂ are selected from the group consisting of a lipophilic substituted nucleotide analog (L), a nucleotide, and a linkage; wherein at least one of R₁ and R₂ is a lipophilic substituted nucleotide analog (L); and wherein L is selected from 5-chloro-5 uracil, 5-bromo-uracil, 5-iodo-uracil, 5-ethyl-uracil, and (E)-5-(2-bromovinyl)-uracil, with the proviso that the oligonucleotide is not d[GCGAA(BrU)(BrU)CGC] where BrU is 5-bromo-uracil.
 109. The method of claim 108, wherein the cancer is selected from the group consisting of basal cell carcinoma; biliary tract cancer; bladder cancer; bone cancer; brain and CNS cancer; breast cancer; cervical cancer; choriocarcinoma; colon and rectum cancer; connective tissue cancer; cancer of the digestive system; endometrial cancer; esophageal cancer; eye cancer; cancer of the head and neck; gastric cancer; intra-epithelial neoplasm; kidney cancer; larynx cancer; leukemia; liver cancer; lung cancer; lymphoma; melanoma; myeloma; neuroblastoma; oral cavity cancer; ovarian cancer; pancreatic cancer; prostate cancer; retinoblastoma; rhabdomyosarcoma; rectal cancer; renal cancer; cancer of the respiratory system; sarcoma; skin cancer; stomach cancer; testicular cancer; thyroid cancer; uterine cancer; cancer of the urinary system; and other carcinomas and sarcomas.
 110. A method of treating or preventing a viral infection in a subject comprising administering a composition of claim
 107. 